Dictionary of Cancer Terms (M - Z)
From National Cancer Institute

click from Dictionary of Cancer Terms (A-M)

M

M protein
An antibody or part of an antibody found in unusually large amounts in the blood or urine of people with multiple myeloma.

macroglobulinemia  (MAK-ro-GLOB-u-li-NE-me-uh)
A condition in which the blood contains high levels of large proteins and is too thick to flow through small blood vessels. One type is Waldenstrom's macroglobulinemia, which is a type of cancer.

macrophage
A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.

mafosfamide
A form of cyclophosphamide that can be administered as an intrathecal infusion. Mafosfamide is being studied as an anticancer drug. It belongs to the family of drugs called alkylating agents.

MAGE-3
A gene found in some types of tumors.

magnesium
In medicine, a mineral used by the body to help maintain muscles, nerves, and bones. It is also used in energy metabolism and protein synthesis.

magnetic resonance imaging  (mag-NET-ik REZ-o-nans IM-a-jing)
MRI. A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as CT or x-ray. MRI is especially useful for imaging the brain, spine, the soft tissue of joints, and the inside of bones. Also called nuclear magnetic resonance imaging.

magnetic resonance perfusion imaging
A special type of magnetic resonance imaging (MRI) that uses an injected dye in order to see blood flow through tissues.

magnetic resonance spectroscopic imaging
MRSI. A noninvasive imaging method that provides information about cellular activity (metabolic information). It is used along with magnetic resonance imaging (MRI) which provides information about the shape and size of the tumor (spacial information). Also called 1H-nuclear magnetic resonance spectroscopic imaging and proton magnetic resonance spectroscopic imaging.

magnetic-targeted carrier
A tiny bead made from particles of iron and carbon that can be attached to an anticancer drug. A magnet applied from outside the body then can direct the drug to the tumor site. This can keep a larger dose of the drug at the tumor site for a longer period of time, and help protect healthy tissue from the side effects of chemotherapy.

maintenance therapy
Treatment that is given to help a primary (original) treatment keep working. Maintenance therapy is often given to help keep cancer in remission.

malabsorption syndrome
A group of symptoms such as gas, bloating, abdominal pain, and diarrhea resulting from the body's inability to properly absorb nutrients.

malignancy
A cancerous tumor that can invade and destroy nearby tissue and spread to other parts of the body.

malignant  (ma-LIG-nant)
Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

malignant ascites
A condition in which fluid containing cancer cells collects in the abdomen.

malignant fibrous cytoma
A soft tissue sarcoma that usually occurs in the limbs, most commonly the legs, and may also occur in the abdomen. Also called malignant fibrous histiocytoma.

malignant fibrous histiocytoma
A soft tissue sarcoma that usually occurs in the limbs, most commonly the legs, and may also occur in the abdomen. Also called malignant fibrous cytoma.

malignant meningioma
A rare, quickly growing tumor that occurs in the membranes that cover and protect the brain and spinal cord (meninges).

malignant mesothelioma
A rare type of cancer in which malignant cells are found in the sac lining the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.

malignant mixed Müllerian tumor
MMMT. A rare type of tumor that is a mixture of carcinoma and sarcoma cells. MMMT usually occurs in the uterus.

malignant peripheral nerve sheath tumor
MPNST. A type of soft tissue sarcoma that develops in cells that form a protective sheath (covering) around peripheral nerves, which are nerves that are outside of the central nervous system (brain and spinal cord).

malnutrition
A disorder caused by a lack of proper nutrition or an inability to absorb nutrients from food.

malondialdehyde
A byproduct of lipid (fat) metabolism in the body. It is also found in many foods and can be present in high amounts in rancid food.

MALT lymphoma
Mucosa-associated lymphoid tissue lymphoma. A type of cancer that arises in cells in mucosal tissue that are involved in antibody production.

mammary
Having to do with the breast.

mammogram  (MAM-o-gram)
An x-ray of the breast.

mammography  (mam-OG-ra-fee)
The use of x-rays to create a picture of the breast.

Mammotome
A device that uses a computer-guided probe to perform breast biopsies. A Mammotome biopsy can be done on an outpatient basis with a local anesthetic, removes only a small amount of healthy tissue, and doesn’t require sutures (stitches) because the incision is very small.

mantle field  (MAN-tul)
The area of the neck, chest, and lymph nodes in the armpit that are exposed to radiation.

margin
The edge or border of the tissue removed in cancer surgery. The margin is described as negative or clean when the pathologist finds no cancer cells at the edge of the tissue, suggesting that all of the cancer has been removed. The margin is described as positive or involved when the pathologist finds cancer cells at the edge of the tissue, suggesting that all of the cancer has not been removed.

marijuana
A type of plant. Extracts of marijuana are being studied for their ability to control severe nausea and vomiting caused by chemotherapy and/or opioid drugs such as morphine.

marimastat
An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Marimastat is a matrix metalloproteinase inhibitor.

marker
A diagnostic indication that disease may develop.

mast cell
A type of white blood cell.

mastectomy  (mas-TEK-toe-mee)
Surgery to remove the breast (or as much of the breast tissue as possible).

mastocytoma
A nodule of mast cells. Mastocytomas can involve the skin, subcutaneous tissue, and sometimes muscle. Also called a mast cell tumor.

matrix metalloproteinase
A member of a group of enzymes that can break down proteins, such as collagen, that are normally found in the spaces between cells in tissues (i.e., extracellular matrix proteins). Because these enzymes need zinc or calcium atoms to work properly, they are called metalloproteinases. Matrix metalloproteinases are involved in wound healing, angiogenesis, and tumor cell metastasis.

MDL 101,731
A drug that belongs to a family of drugs called ribonucleotide reductase inhibitors.

MDX-060
A monoclonal antibody that is being studied in the treatment of some lymphomas. Monoclonal antibodies are produced in the laboratory and can locate and bind to cancer cells.

mean
A statistics term. The average value in a set of measurements. The mean is the sum of a set of numbers divided by how many numbers are in the set.

mean survival time
The average time that patients in a clinical study remained alive. The time is measured beginning either at diagnosis or the start of treatment.

measurable disease
A tumor that can be accurately measured in size. This information can be used to judge response to treatment.

mechlorethamine
An anticancer drug that belongs to the family of drugs called alkylating agents.

MEDI-507
A monoclonal antibody that is being studied in the treatment of certain lymphoproliferative disorders and psoriasis. Also called siplizumab.

medial supraclavicular lymph node
A lymph node located above the collar bone and between the center of the body and a line drawn through the nipple to the shoulder.

median
A statistics term. The middle value in a set of measurements.

median survival time
The time from either diagnosis or treatment at which half of the patients with a given disease are found to be, or expected to be, still alive. In a clinical trial, median survival time is one way to measure how effective a treatment is.

mediastinal pleura
The thin membrane that lines the chest cavity in the area between the lungs.

mediastinoscopy  (MEE-dee-a-stin-AHS-ko-pee)
A procedure in which a tube is inserted into the chest to view the organs in the area between the lungs and nearby lymph nodes. The tube is inserted through an incision above the breastbone. This procedure is usually performed to get a tissue sample from the lymph nodes on the right side of the chest.

mediastinum  (mee-dee-a-STYE-num)
The area between the lungs. The organs in this area include the heart and its large blood vessels, the trachea, the esophagus, the bronchi, and lymph nodes.

medical castration
Refers to the use of drugs to suppress the function of the ovaries or testicles.

medical oncologist  (MED-i-kul on-KOL-o-jist)
A doctor who specializes in diagnosing and treating cancer using chemotherapy, hormonal therapy, and biological therapy. A medical oncologist often is the main health care provider for a person who has cancer. A medical oncologist also may coordinate treatment provided by other specialists.

medroxyprogesterone
A hormonal anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called progestins.

medullary breast carcinoma  (MED-yoo-LAIR-ee)
A rare type of breast cancer that often can be treated successfully. It is marked by lymphocytes (a type of white blood cell) in and around the tumor that can be seen when viewed under a microscope.

medullary thyroid cancer  (MED-yoo-LAIR-ee)
Cancer that develops in C cells of the thyroid. The C cells make a hormone (calcitonin) that helps maintain a healthy level of calcium in the blood.

medulloblastoma  (MED-yoo-lo-blas-TOE-ma)
A malignant brain tumor that begins in the lower part of the brain and that can spread to the spine or to other parts of the body. Medulloblastomas are a type of primitive neuroectodermal tumor (PNET).

mega-voltage linear accelerator
MeV linear accelerator. A machine that creates high-energy radiation to treat cancer, using electricity to form a stream of fast-moving subatomic particles. Also called linear accelerator or a linac.

megestrol
A drug that belongs to the group of hormones called progestins, used as hormone therapy to block estrogen and to suppress the effects of estrogen and androgens. It is also used to stimulate the appetite in people with cancer.

meiosis
A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell. Meiosis occurs during formation of egg and sperm cells in mammals.

melanin  (MEL-a-nin)
The substance that gives color to skin and eyes.

melanocyte  (mel-AN-o-site)
A cell in the skin and eyes that produces and contains the pigment called melanin.

melanoma
A form of skin cancer that arises in melanocytes, the cells that produce pigment. Melanoma usually begins in a mole.

melanoma vaccine
A cancer vaccine prepared from human melanoma cancer cells. It can be used alone or with other therapy in treating melanoma.

melphalan
An anticancer drug that belongs to the family of drugs called alkylating agents.

membrane
A very thin layer of tissue that covers a surface.

MEN-10755
An anticancer drug that belongs to the family of drugs called antitumor antibiotics.

MEN1 syndrome
Multiple endocrine neoplasia type 1 syndrome. A rare, inherited disorder that affects the endocrine glands and can cause tumors in the parathyroid and pituitary glands and the pancreas. These tumors (usually benign) cause the glands to secrete high levels of hormones, which can lead to other medical problems, such as kidney stones, fertility problems, and severe ulcers. In some cases, tumors inside the pancreas can become cancerous. Also called multiple endocrine adenomatosis and Wermer's syndrome.

meningeal
Refers to the meninges, the tissue covering the brain and spinal cord.

meningeal metastases
Cancer that has spread from the original (primary) tumor to the tissue covering the brain, spinal cord, or both.

meninges  (meh-NIN-jeez)
The three membranes that cover and protect the brain and spinal cord.

meningioma  (meh-nin-jee-O-ma)
A type of tumor that occurs in the meninges, the membranes that cover and protect the brain and spinal cord. Meningiomas usually grow slowly.

menopausal hormone therapy
Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called hormone replacement therapy or HRT.

menopause  (MEN-o-pawz)
The time of life when a woman's menstrual periods stop permanently. Also called "change of life."

menorrhagia
Abnormally heavy menstrual bleeding.

menstrual cycle  (MEN-stroo-al)
The monthly cycle of hormonal changes from the beginning of one menstrual period to the beginning of the next.

menstruation  (MEN-stroo-AY-shun)
Periodic discharge of blood and tissue from the uterus. From puberty until menopause, menstruation occurs about every 28 days when a woman is not pregnant.

mental health counselor
A specialist who can talk with patients and their families about emotional and personal matters, and can help them make decisions.

mercaptopurine
An anticancer drug that belongs to the family of drugs called antimetabolites.

mercury
A silver-white, poisonous metal that is a liquid at ordinary temperatures. It is commonly used in thermometers and amalgams, and has been used as an ingredient in some homeopathic medicines and in very small amounts as a preservative in viral vaccines.

Merkel cell cancer
A rare type of cancer that develops on or just beneath the skin.

mesenchymal
Refers to cells that develop into connective tissue, blood vessels, and lymphatic tissue.

mesenteric membrane
The peritoneal membrane that attaches the intestines to the abdominal wall near the back.

mesna
A drug that helps protect the kidneys and bladder from the toxic effects of anticancer drugs such as ifosfamide and cyclophosphamide.

mesonephroma
A rare type of tumor, usually of the female genital tract, in which the inside of the cells looks clear when viewed under a microscope. Also called clear cell carcinoma and clear cell adenocarcinoma.

mesothelioma
A benign (noncancerous) or malignant (cancerous) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the air increases the risk of developing malignant mesothelioma.

metabolic
Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).

metabolic acidosis  (met-ah-BOL-ik as-id-O-sis)
A condition in which the blood is too acidic. It may be caused by severe illness or sepsis (bacteria in the bloodstream).

metabolic disorder
A condition in which normal metabolic processes are disrupted, usually because of a missing enzyme.

metabolic therapy
Treatment to correct changes in metabolism that can be caused by disease.

metabolism
The total of all chemical changes that take place in a cell or an organism. These changes produce energy and basic materials needed for important life processes.

metaplasia
A change of cells to a form that does not normally occur in the tissue in which it is found.

metaplastic carcinoma
A general term used to describe cancer that begins in cells that have changed into another cell type (for example, a squamous cell of the esophagus changing to resemble a cell of the stomach). In some cases, metaplastic changes alone may mean there is an increased chance of cancer developing at the site.

metastasectomy  (meh-TAS-ta-SEC-tuh-mee)
Surgery to remove one or more metastases (tumors formed from cells that have spread from the primary tumor). When all metastases are removed, it is called a complete metastasectomy.

metastasis  (meh-TAS-ta-sis)
The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-ta-seez).

metastasize  (meh-TAS-ta-size)
To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

metastatic  (MET-uh-STAT-ik)
Having to do with metastasis, which is the spread of cancer from one part of the body to another.

metastatic cancer
Cancer that has spread from the place in which it started to other parts of the body.

metasynchronous
Occurring at nearly the same time.

meteorism
Swelling of the abdomen caused by gas in the intestines or peritoneal cavity. Also called tympanites.

methotrexate
An anticancer drug that belongs to the family of drugs called antimetabolites.

methoxsalen
A drug used in ultraviolet light therapy.

methoxypolyethylene glycol epoetin beta
A substance that is being studied in the treatment of anemia in patients who are receiving chemotherapy. It is a form of erythropoietin (a substance produced in the kidneys that stimulates the production of red blood cells) that has been changed in the laboratory. Also called Ro 50-3821.

methyl-5-aminolevulinate
A drug used in photodynamic therapy; it is absorbed by tumor cells and, when exposed to light, becomes active and kills the cancer cells.

methylphenidate
A drug that is a central nervous system stimulant.

methylprednisolone
A corticosteroid hormone replacement.

metoclopramide
A drug that prevents or reduces nausea and vomiting.

metronidazole
A drug used to treat bacterial, fungal, and parasitic infections. It is also being studied in the treatment of some cancers.

metronomic therapy
Continuous or frequent treatment with low doses of anticancer drugs, often given with other methods of therapy.

Mexican valerian
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, garden valerian, Indian valerian, Pacific valerian, garden heliotrope, and Valerianae radix.

MG98
An anticancer drug that belongs to the family of drugs called antisense compounds. These drugs interfere with production of certain proteins in the cell.

microcalcification  (MY-krow-kal-si-fi-KAY-shun)
A tiny deposit of calcium in the breast that cannot be felt but can be detected on a mammogram. A cluster of these very small specks of calcium may indicate that cancer is present.

microgram
One millionth of a gram.

micrometastases
Small numbers of cancer cells that have spread from the primary tumor to other parts of the body and are too few to be picked up in a screening or diagnostic test.

micromolar
A concentration of 10-6 (one millionth) molecular weight per liter (mol/L).

microorganism
An organism that can be seen only through a microscope. Microorganisms include bacteria, protozoa, algae, and fungi. Although viruses are not considered living organisms, they are sometimes classified as microorganisms.

microsatellite
A short sequence of DNA, usually 1 to 4 basepairs (a unit of DNA), that is repeated together in a row along the DNA molecule. There is variation from person to person in the number of repeats. There are hundreds of places in human DNA that contain microsatellites.

microsatellite instability
MSI. A change that occurs in the DNA of certain cells (such as tumor cells) in which the number of repeats of microsatellites (short, repeated sequences of DNA) is different than the number of repeats that was in the DNA when it was inherited. The cause of MSI may be a defect in the ability to repair mistakes made when DNA is copied in the cell.

microscopic
Too small to be seen without a microscope.

microstaging
A technique used to help determine the stage (extent) of melanoma and certain squamous cell cancers. A sample of skin that contains tumor tissue is examined under a microscope to find out how thick the tumor is and/or how deeply the tumor has grown into the skin or connective tissues.

microwave therapy
A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs. Also called microwave thermotherapy.

microwave thermotherapy
A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs. Also called microwave therapy.

mifepristone
An anticancer drug that blocks the action of progesterone, a hormone that affects the growth of some cancers.

milk thistle
A plant that has been used in some cultures to treat certain medical problems, including stomach, liver, and gallbladder disorders. The active extract of milk thistle seeds is called silymarin. It is being studied in the prevention of liver damage caused by some cancer treatments. Also called Silybum marianum.

milligram
A measure of weight. A milligram is approximately 450,000 times smaller than a pound and 28,000 times smaller than an ounce.

milliliter
A measure of volume for a liquid. A milliliter is approximately 950 times smaller than a quart and 30 times smaller than a fluid ounce. A milliliter of liquid and a cubic centimeter (cc) of liquid are the same.

millimeter
A measure of length in the metric system. A millimeter is one thousandth of a meter. There are 25 millimeters in an inch.

mindfulness relaxation
A type of meditation based on the concept of being “mindful,” or having increased awareness, of the present. It uses breathing methods, guided imagery, and other practices to relax the body and mind and help reduce stress.

mineral
A nutrient required to maintain health.

misoprostol
A radioprotective agent that belongs to the family of drugs called prostaglandins.

mistletoe
A semiparasitic plant that grows on some types of trees. Mistletoe extracts are being studied as treatments for cancer.

mistletoe lectin
A substance that comes from the mistletoe plant and that is being studied as a treatment for cancer. A lectin is a complex molecule that has both protein and sugars. Lectins are able to bind to the outside of a cell and cause biochemical changes in it. Lectins are made by both animals and plants.

mitochondria
Parts of a cell where aerobic production (also called cell respiration) takes place.

mitolactol
An anticancer drug that belongs to the family of drugs called alkylating agents.

mitomycin
An anticancer drug that belongs to the family of drugs called antitumor antibiotics.

mitosis
The process of division of somatic cells in which each daughter cell receives the same amount of DNA as the parent cell.

mitotane
An anticancer drug used in treating adrenocortical cancer and ACTH-producing pituitary tumors (Cushing's disease).

mitotic activity
Having to do with the presence of dividing (proliferating) cells. Cancerous tissue generally has more mitotic activity than normal tissues.

mitotic inhibitor
A drug that inhibits cell growth by stopping cell division. Mitotic inhibitors are used as treatments for cancer. Also called antimitotic or antimicrotubule agents and taxanes. Docetaxel and paclitaxel are mitotic inhibitors.

mitoxantrone
An anticancer drug that belongs to the family of drugs called antitumor antibiotics.

mivobulin isethionate
An anticancer drug that belongs to the family of drugs called mitotic inhibitors. Also called CI-980.

mixed glioma
A brain tumor that occurs in more than one type of brain cell, including astrocytes, ependymal cells, and oligodendrocytes.

MLN2704
A substance that is being studied as a treatment for prostate cancer. It belongs to the family of drugs called antibody conjugates.

modafinil
A drug that is being studied as a treatment for fatigue in patients with cancer. It belongs to the family of drugs called stimulants.

modality
A method of treatment. For example, surgery and chemotherapy are treatment modalities.

modified radical mastectomy  (mas-TEK-toe-mee)
Surgery for breast cancer in which the breast, most or all of the lymph nodes under the arm, and the lining over the chest muscles are removed. Sometimes the surgeon also removes part of the chest wall muscles.

Mohs surgery
A surgical technique used to treat skin cancer. Individual layers of cancerous tissue are removed and examined under a microscope one at a time until all cancerous tissue has been removed.

molar pregnancy
A rare cancer in women of childbearing age in which cancer cells grow in the tissues that are formed in the uterus after conception. Also called gestational trophoblastic disease, gestational trophoblastic neoplasia, gestational trophoblastic tumor, or choriocarcinoma.

mold
A form of fungus. Some molds can cause disease in humans.

mole
A benign growth on the skin (usually tan, brown, or flesh-colored) that contains a cluster of melanocytes and surrounding supportive tissue.

molecular mass
The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively. For example, the molecular mass of water, which has two atoms of hydrogen and one atom of oxygen, is 18 (i.e., 2 + 16).

molecular risk assessment
A procedure in which biomarkers (for example, biological molecules or changes in tumor cell DNA) are used to estimate a person’s risk for developing cancer. Specific biomarkers may be linked to particular types of cancer.

molecularly targeted therapy
In cancer treatment, substances that kill cancer cells by targeting key molecules involved in cancer cell growth.

molecule
The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom). Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.

monoclonal antibody  (MAH-no-KLO-nul AN-tih-BAH-dee)
A laboratory-produced substance that can locate and bind to cancer cells wherever they are in the body. Many monoclonal antibodies are used in cancer detection or therapy; each one recognizes a different protein on certain cancer cells. Monoclonal antibodies can be used alone, or they can be used to deliver drugs, toxins, or radioactive material directly to a tumor.

monoclonal antibody 3F8
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

monocyte
A type of white blood cell.

Montanide ISA-51
A drug used in vaccine therapy to stimulate the immune system.

morbidity
A disease or the incidence of disease within a population. Morbidity also refers to adverse effects caused by a treatment.

Morinda citrifolia
A tropical shrub. An extract from the fruit is being studied as a treatment for cancer, and extracts from the fruit, leaves, or roots have been used in some cultures to treat other diseases. Also called noni.

morphine
A narcotic drug used in the treatment of pain.

morphology
The science of the form and structure of organisms (plants, animals, and other forms of life).

motexafin gadolinium
A substance that makes tumor cells more sensitive to radiation; it can also enhance tumor images using magnetic resonance imaging (MRI). Motexafin gadolinium belongs to the family of drugs called metalloporphyrin complexes. Also called gadolinium texaphyrin.

motor
In medicine, having to do with the movement of body parts.

moxifloxacin
A drug used to treat bacterial infections. It belongs to the family of drugs called fluoroquinolone antibiotics.

MPNST
Malignant peripheral nerve sheath tumor. A type of soft tissue sarcoma that develops in cells that form a protective sheath (covering) around peripheral nerves, which are nerves that are outside of the central nervous system (brain and spinal cord).

MRI
Magnetic resonance imaging (mag-NET-ik REZ-o-nans IM-a-jing). A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as CT or x-ray. MRI is especially useful for imaging the brain, spine, the soft tissue of joints, and the inside of bones. Also called nuclear magnetic resonance imaging.

MRSI
Magnetic resonance spectroscopic imaging. A noninvasive imaging method that provides information about cellular activity (metabolic information). It is used along with magnetic resonance imaging (MRI) which provides information about the shape and size of the tumor (spacial information).

MS 209
A substance that is being studied for its ability to make cancer cells respond better to chemotherapy drugs to which they have become resistant. It belongs to the family of drugs called quinolone antibiotics.

MS-275
A substance that is being studied in the treatment of cancers of the blood. It belongs to the family of drugs called histone deacetylase inhibitors.

mucin/peptide
A protein/sugar compound made by some cancer cells.

mucinous  (MYOO-sin-us)
Containing or resembling mucin, the main compound in mucus.

mucinous carcinoma  (MYOO-sin-us kar-sin-O-ma)
A type of cancer that begins in cells that line certain internal organs and produce mucin (the main component of mucus).

mucosa
The moist tissue that lines some organs and body cavities (such as the nose, mouth, lungs) and makes mucus (a thick, slippery fluid). Also called mucous membrane.

mucosa-associated lymphoid tissue lymphoma
MALT lymphoma. A type of cancer that arises in cells in mucosal tissue that are involved in antibody production.

mucositis
A complication of some cancer therapies in which the lining of the digestive system becomes inflamed. Often seen as sores in the mouth.

mucous membrane  (MYOO-kus)
The moist tissue that lines some organs and body cavities (such as the nose, mouth, lungs) and makes mucus (a thick, slippery fluid). Also called mucosa.

mucus
A thick, slippery fluid produced by the membranes that line certain organs of the body, including the nose, mouth, throat, and vagina.

muJ591 monoclonal antibody
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

Müllerian tumor
A rare cancer of the uterus, ovary, or fallopian tubes.

multicenter study
A clinical trial that is carried out at more than one medical institution.

multicentric breast cancer  (mul-tee-SEN-trik)
Breast cancer in which there is more than one tumor, all of which have formed separately from one another. The tumors are likely to be in different quadrants (sections) of the breast. Multicentric breast cancers are rare.

multidisciplinary
In medicine, a term used to describe a treatment planning approach or team that includes a number of doctors and other health care professionals who are experts in different specialties (disciplines). In cancer treatment, the primary disciplines are medical oncology (treatment with drugs), surgical oncology (treatment with surgery), and radiation oncology (treatment with radiation).

multidisciplinary opinion
A treatment planning approach in which a number of doctors who are experts in different specialties (disciplines) review and discuss the medical condition and treatment options of a patient. In cancer treatment, a multidisciplinary opinion may include that of a medical oncologist (who provides cancer treatment with drugs), a surgical oncologist (who provides cancer treatment with surgery), and a radiation oncologist (who provides cancer treatment with radiation). Also called a tumor board review.

multidrug resistance
Adaptation of tumor cells to anticancer drugs in ways that make the drugs less effective.

multidrug resistance inhibition
Treatment used to make cancer cells less resistant to anticancer drugs.

multifocal breast cancer  (mul-tee-FO-kal)
Breast cancer in which there is more than one tumor, all of which have arisen from one original tumor. The tumors are likely to be in the same quadrant (section) of the breast.

multimodality treatment
Therapy that combines more than one method of treatment.

multiple endocrine adenomatosis
A rare, inherited disorder that affects the endocrine glands and can cause tumors in the parathyroid and pituitary glands and the pancreas. These tumors (usually benign) cause the glands to secrete high levels of hormones, which can lead to other medical problems, such as kidney stones, fertility problems, and severe ulcers. In some cases, tumors inside the pancreas can become cancerous. Also called multiple endocrine neoplasia type 1 syndrome and Wermer's syndrome.

multiple endocrine neoplasia syndrome
An inherited tendency to develop thyroid cancer and other cancers of the endocrine system. The altered gene can be detected with a blood test.

multiple endocrine neoplasia type 1 syndrome
MEN1 syndrome. A rare, inherited disorder that affects the endocrine glands and can cause tumors in the parathyroid and pituitary glands and the pancreas. These tumors (usually benign) cause the glands to secrete high levels of hormones, which can lead to other medical problems, such as kidney stones, fertility problems, and severe ulcers. In some cases, tumors inside the pancreas can become cancerous. Also called multiple endocrine adenomatosis and Wermer's syndrome.

multiple myeloma  (mye-eh-LO-ma)
Cancer that arises in plasma cells (white blood cells that produce antibodies).

multiple sclerosis
A disorder of the central nervous system marked by weakness, numbness, a loss of muscle coordination, and problems with vision, speech, and bladder control. Multiple sclerosis is thought to be an autoimmune disease in which the body's immune system destroys myelin. Myelin is a substance that contains both protein and fat (lipid), serving as a nerve insulator and helping in the transmission of nerve signals.

multiplicity
A large number or variety.

mung bean
A type of bean grown in warm climates, usually for its seed and for bean sprouts. Mung bean may have anticancer effects.

muromonab-CD3 monoclonal antibody
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

musculoskeletal
Having to do with muscles, bones, and cartilage.

mutate
To change the genetic material of a cell. The changes (mutations) can be harmful, beneficial, or have no effect.

mutation
Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

myalgia  (my-AL-juh)
Pain in a muscle or group of muscles.

mycophenolate mofetil
A drug that is being studied for its effectiveness in preventing graft-versus-host disease and autoimmune disorders.

mycosis fungoides  (mye-KO-sis fun-GOY-deez)
A type of non-Hodgkin's lymphoma that first appears on the skin and can spread to the lymph nodes or other organs such as the spleen, liver, or lungs.

mycostatin
A drug that treats infections caused by fungi.

myelin  (MYE-eh-lin)
The fatty substance that covers and protects nerves.

myeloablation
A severe form of myelosuppression. Myelosuppression is a condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets. It is a side effect of some cancer treatments.

myelodysplasia
Abnormal bone marrow cells that may lead to myelogenous leukemia.

myelodysplastic syndrome  (MYE-eh-lo-dis-PLAS-tik SIN-drome)
Disease in which the bone marrow does not function normally. Also called preleukemia or smoldering leukemia.

myelofibrosis
A disorder in which the bone marrow is replaced by fibrous tissue.

myelogenous  (my-eh-LAH-jen-us)
Having to do with, produced by, or resembling the bone marrow. Sometimes used as a synonym for myeloid; for example, acute myeloid leukemia and acute myelogenous leukemia are the same disease.

myelogram  (MY-eh-lo-gram)
An x-ray of the spinal cord after an injection of dye into the space between the lining of the spinal cord and brain.

myeloid  (MY-eh-loyd)
Having to do with or resembling the bone marrow. May also refer to certain types of hematopoietic (blood-forming) cells found in the bone marrow. Sometimes used as a synonym for myelogenous; for example, acute myeloid leukemia and acute myelogenous leukemia are the same disease.

myeloma
Cancer that arises in plasma cells, a type of white blood cell.

myeloproliferative disorder
A disease in which too many blood cells are made in the bone marrow.

myelosclerosis with myeloid metaplasia
A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and blood is made in organs such as the liver and the spleen, instead of in the bone marrow. This disease is marked by an enlarged spleen and progressive anemia. Also called chronic idiopathic myelofibrosis, agnogenic myeloid metaplasia, primary myelofibrosis, and idiopathic myelofibrosis.

myelosuppression
A condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets. Myelosuppression is a side effect of some cancer treatments. When myelosuppression is severe, it is called myeloablation.

myelosuppressive therapy
Treatment that inhibits blood cell production.

myometrium  (mye-o-MEE-tree-um)
The muscular outer layer of the uterus.

N

N-acetylcysteine
An antioxidant drug that may keep cancer cells from developing or reduce the risk of growth of existing cancer.

N-acetyldinaline
A substance that is being studied as an anticancer drug in the treatment of non-small cell lung cancer. Also called CI-994.

N-butyl-N-(4-hydroxybutyl) nitrosamine
A substance that is used in cancer research to cause bladder tumors in laboratory animals. This is done to test new diets, drugs, and procedures for use in cancer prevention and treatment.

naloxone
A substance that is being studied as a treatment for constipation caused by narcotic medications. It belongs to the family of drugs called narcotic antagonists.

nanogram
A measure of weight. One nanogram weighs a billion times less than one gram, and almost a trillion-times less than a pound.

narcotic
An agent that causes insensibility or stupor; usually refers to opioids given to relieve pain.

nasal
By or having to do with the nose.

nasopharynx  (NAY-zo-fair-inks)
The upper part of the throat behind the nose. An opening on each side of the nasopharynx leads into the ear.

nasoscope
A thin lighted tube used to examine the nose. Also called a rhinoscope.

nasoscopy
A procedure in which a thin, lighted tube is inserted into the nose to look for abnormal areas. Also called rhinoscopy.

National Cancer Institute
NCI. The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. NCI conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://cancer.gov.

National Institutes of Health
NIH. The National Institutes of Health, the focal point of biomedical research in the United States, conducts research in its own laboratories; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the NIH Web site at http://www.nih.gov.

natural killer cell
NK cell. A type of white blood cell that contains granules with enzymes that can kill tumor cells or microbial cells. Also called a large granular lymphocyte.

NB1011
A substance that is being studied for its ability to make cancer cells respond to drugs to which they have become resistant. It belongs to the family of drugs called nucleoside analogs.

NBI-3001
A substance that is being studied in the treatment of cancer. It is made by combining interleukin 4 with a bacterial toxin, and belongs to the family of drugs called recombinant chimeric proteins. Also called interleukin-4 PE38KDEL immunotoxin and interleukin-4 PE38KDEL cytotoxin.

NCI
National Cancer Institute. NCI, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. NCI conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://cancer.gov.

nebulizer
A device used to turn liquid into a fine spray.

neck dissection  (dye-SEK-shun)
Surgery to remove lymph nodes and other tissues in the neck.

necrosis  (ne-KRO-sis)
Refers to the death of living tissues.

needle biopsy
The removal of tissue or fluid with a needle for examination under a microscope. Also called fine-needle aspiration.

needle-localized biopsy
A procedure that uses very thin needles or guide wires to mark the location of an abnormal area of tissue so it can be surgically removed. An imaging device is used to place the wire in or around the abnormal area. Needle localization is used when the doctor cannot feel the mass of abnormal tissue.

negative axillary lymph node
A lymph node in the armpit that is free of cancer.

negative test result
A test result that fails to show the specific disease or condition for which the test was being done.

nelarabine
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called antimetabolites. Also called 506U78.

nelfinavir mesylate
A drug that interferes with the ability of a virus to make copies of itself.

neoadjuvant therapy  (NEE-o-AD-joo-vant)
Treatment given before the primary treatment. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy.

neoplasia  (NEE-o-PLAY-zha)
Abnormal and uncontrolled cell growth.

neoplasm
An abnormal mass of tissue that results from excessive cell division. Neoplasms may be benign (not cancerous), or malignant (cancerous). Also called tumor.

neoplastic meningitis
A condition in which cancer cells spread into the meninges (membranes that surround the brain and spinal cord).

nephrectomy  (neh-FREK-tuh-mee)
Surgery to remove a kidney or part of a kidney. In a partial nephrectomy, part of one kidney or a tumor is removed, but not an entire kidney. In a simple nephrectomy, one kidney is removed. In a radical nephrectomy, an entire kidney, nearby adrenal gland and lymph nodes, and other surrounding tissue are removed. In a bilateral nephrectomy, both kidneys are removed.

nephrologist  (neh-FROL-uh-jist)
A doctor who specializes in diagnosing and treating kidney disease.

nephrotomogram  (nef-ro-TOE-mo-gram)
A series of x-rays of the kidneys. The x-rays are taken from different angles and show the kidneys clearly, without the shadows of the organs around them.

nephrotoxic
Poisonous or damaging to the kidney.

nephroureterectomy
Surgery to remove a kidney and its ureter. Also called ureteronephrectomy.

nerve
A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.

nerve block
A procedure in which medicine is injected directly into or around a nerve or into the spine to block pain.

nerve cell
A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. Also called a neuron.

nerve grafting
Replacing a damaged nerve with a section of a healthy nerve that has been removed from another part of the body. This procedure is being studied in the prevention of erectile dysfunction in men having surgery for prostate cancer.

nerve-sparing radical prostatectomy
Surgery to remove the prostate in which an attempt is made to save the nerves that help cause penile erections.

nerve-sparing surgery  (SER-juh-ree)
A type of surgery that attempts to save the nerves near the tissues being removed.

neural
Having to do with nerves or the nervous system, including the brain and the spinal cord.

neuro-oncologist  (NOO-ro-on-KOL-o-jist)
A doctor who specializes in diagnosing and treating brain tumors and other tumors of the nervous system.

neurobehavioral
Having to do with the way the brain affects emotion, behavior, and learning. Some cancers or their treatment may cause neurobehavioral problems.

neuroblastoma
Cancer that arises in immature nerve cells and affects mostly infants and children.

neurocognitive
Having to do with the ability to think and reason. This includes the ability to concentrate, remember things, process information, learn, speak, and understand.

neuroectodermal tumor
A tumor of the central or peripheral nervous system.

neuroendocrine  (NOO-ro-EN-do-krin)
Having to do with the interactions between the nervous system and the endocrine system. Neuroendocrine describes certain cells that release hormones into the blood in response to stimulation of the nervous system.

neuroendocrine tumor
A tumor derived from cells that release a hormone in response to a signal from the nervous system. Some examples of neuroendocrine tumors are carcinoid tumors, islet cell tumors, medullary thyroid carcinoma, and pheochromocytoma. These tumors secrete hormones in excess, causing a variety of symptoms.

neuroepithelial
Having to do with tissue made up of sensory cells, such as tissue found in the ear, nose, and tongue.

neurofibroma
A benign tumor that develops from the cells and tissues that cover nerves.

neurofibromatosis type 1
NF1. A rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone, and skin.

neurofibromatosis type 2
NF2. A genetic condition in which tumors form on the nerves of the inner ear and cause loss of hearing and balance. Tumors may also occur in the brain and on nerves in the skull and spinal cord, and may cause loss of speech, eye movement, and the ability to swallow. Also called acoustic neurofibromatosis.

neurologic  (noor-uh-LOJ-ik)
Having to do with nerves or the nervous system.

neurological exam
A series of questions and tests to check brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, ability to walk, and how well the muscles, sensory systems, and deep tendon reflexes work.

neurologist  (noo-ROL-o-jist)
A doctor who specializes in the diagnosis and treatment of disorders of the nervous system.

neuroma  (noo-RO-ma)
A tumor that arises in nerve cells.

neuron
A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. Also called a nerve cell.

neuropathologist
A pathologist who specializes in diseases of the nervous system. A pathologist identifies disease by studying cells and tissues under a microscope.

neuropathy
A problem in peripheral nerve function (any part of the nervous system except the brain and spinal cord) that causes pain, numbness, tingling, swelling, and muscle weakness in various parts of the body. Neuropathies may be caused by physical injury, infection, toxic substances, disease (e.g., cancer, diabetes, kidney failure, or malnutrition), or drugs such as anticancer drugs. Also called peripheral neuropathy.

neuropeptide
A member of a class of protein-like molecules made in the brain. Neuropeptides consist of short chains of amino acids, with some functioning as neurotransmitters and some functioning as hormones.

neuroradiologist
A doctor trained in radiology who specializes in creating and interpreting pictures of the nervous system. The pictures are produced using forms of radiation, such as x-rays, sound waves, or other types of energy.

neurosurgeon  (NOO-ro-SER-jun)
A doctor who specializes in surgery on the brain, spine, and other parts of the nervous system.

neurotoxicity
The tendency of some treatments to cause damage to the nervous system.

neurotoxin
A substance that is poisonous to nerve tissue.

neurotropism
An ability to invade and live in neural tissue. This term is usually used to describe the ability of viruses to infect nerve tissue.

neutropenia
An abnormal decrease in the number of neutrophils, a type of white blood cell.

neutrophil  (NOO-tro-fil)
A type of white blood cell.

nevus  (NEE-vus)
A benign growth on the skin, such as a mole. A mole is a cluster of melanocytes and surrounding supportive tissue that usually appears as a tan, brown, or flesh-colored spot on the skin. The plural of nevus is nevi (NEE-vye).

NF1
Neurofibromatosis type 1. A rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone, and skin.

NG-monomethyl-L-arginine
An amino acid derivative used to counteract high blood pressure caused by interleukin-2.

niacinamide
A vitamin being studied to increase the effect of radiation therapy on tumor cells. Also called nicotinamide.

nicotinamide
A vitamin being studied to increase the effect of radiation therapy on tumor cells. Also called niacinamide.

NIH
National Institutes of Health. NIH, the focal point of biomedical research in the United States, conducts research in its own laboratories; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the NIH Web site at http://www.nih.gov.

nilutamide  (nye-LOO-ta-mide)
A drug that blocks the effects of male hormones in the body. It belongs to the family of drugs called antiandrogens.

nimodipine
Belongs to a family of drugs called calcium channel blockers. It is being investigated for use with anticancer drugs to prevent or overcome drug resistance and improve response to chemotherapy.

nipple
In anatomy, the small raised area in the center of the breast through which milk can flow to the outside.

nipple discharge
Fluid coming from the nipple.

nitric acid
A toxic, corrosive, colorless liquid used to make fertilizers, dyes, explosives, and other chemicals.

nitrocamptothecin
An alkaloid drug belonging to a class of anticancer agents called topoisomerase inhibitors.

nitrosourea  (nye-TRO-so-yoo-REE-ah)
An anticancer drug that can cross the blood-brain barrier. Carmustine and lomustine are nitrosoureas.

NK cell
Natural killer cell. A type of white blood cell that contains granules with enzymes that can kill tumor cells or microbial cells. Also called a large granular lymphocyte.

NMRI
Nuclear magnetic resonance imaging. A procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body.

node-negative
Cancer that has not spread to the lymph nodes.

node-positive
Cancer that has spread to the lymph nodes.

nodular parenchyma
A small mass of tissue within a gland or organ that carries out the specialized functions of the gland or organ.

nodule  (NOD-yool)
A growth or lump that may be cancerous or noncancerous.

nolatrexed
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called thymidylate synthase inhibitors. Also called AG337.

non-Hodgkin's lymphoma
A group of cancers of the lymphoid system, including acute lymphoblastic leukemia, B-cell lymphoma, Burkitt's lymphoma, diffuse cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, lymphoblastic lymphoma, mantle cell lymphoma, mycosis fungoides, post-transplantation lymphoproliferative disorder, small non-cleaved cell lymphoma, and T-cell lymphoma.

non-small cell lung cancer
A group of lung cancers that includes squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.

nonblinded
Describes a clinical trial or other experiment in which the researchers know what treatments are being given to each study subject or experimental group. If human subjects are involved, they know what treatments they are receiving.

nonconsecutive case series
A clinical study that includes some, but not all, of the eligible patients identified by the researchers during the study registration period. This type of study does not usually have a control group.

noncontiguous lymphoma
Lymphoma in which the lymph nodes containing cancer are not next to each other, but are on the same side of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).

nonhematologic cancer
Cancer that does not begin in the blood or bone marrow.

noni
Morinda citrifolia. A tropical shrub. An extract from the fruit is being studied as a treatment for cancer, and extracts from the fruit, leaves, or roots have been used in some cultures to treat other diseases.

nonlytic
In biology, refers to viruses that do not kill infected cells by disrupting their plasma membranes.

nonmalignant
Not cancerous.

nonmalignant hematologic disorder
A disorder of the blood. Some nonmalignant hematologic disorders may lead to leukemia.

nonmelanoma skin cancer
Skin cancer that arises in basal cells or squamous cells but not in melanocytes (pigment-producing cells of the skin).

nonmelanomatous
Having to do with skin cancer that develops in basal cells or squamous cells but not in melanocytes (pigment-producing cells of the skin).

nonmetastatic
Cancer that has not spread from the primary (original) site to other sites in the body.

nonopioid
A drug that is not an opioid. Examples include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDS), such as aspirin and ibuprofen.

nonprescription
A medicine that can be bought without a doctor's order. Examples include some analgesics (pain relievers). Also called over-the-counter (OTC).

nonrandomized clinical trial
A clinical trial in which the participants are not assigned by chance to different treatment groups. Participants may choose which group they want to be in, or they may be assigned to the groups by the researchers.

nonseminoma  (non-sem-ih-NO-ma)
A group of testicular cancers that begin in the germ cells (cells that give rise to sperm). Nonseminomas are identified by the type of cell in which they begin and include embryonal carcinoma, teratoma, choriocarcinoma, and yolk sac carcinoma.

nonspecific immune cell
A cell (such as a phagocyte or a macrophage) that responds to many antigens, not just one antigen.

nonsteroidal anti-inflammatory drug
NSAID. A drug that decreases fever, swelling, pain, and redness.

nonsteroidal aromatase inhibitor
A drug that decreases the production of sex hormones (estrogen or testosterone) and slows the growth of tumors that need sex hormones to grow.

nontoxic
Not harmful or destructive.

novobiocin
An antibiotic drug used to treat infection.

NPO
A Latin abbreviation for “nothing by mouth.”

NR-LU-10 antigen
A protein found on the surface of some cancers.

NSAID
Nonsteroidal anti-inflammatory drug. A drug that decreases fever, swelling, pain, and redness.

nuclear grade
An evaluation of the size and shape of the nucleus in tumor cells and the percentage of tumor cells that are in the process of dividing or growing. Cancers with low nuclear grade grow and spread less quickly than cancers with high nuclear grade.

nuclear magnetic resonance imaging
NMRI. A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. NMRI makes better images of organs and soft tissue than other scanning techniques, such as CT or X-ray. NMRI is especially useful for imaging the brain, spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging (MRI).

nuclear medicine scan
A method of diagnostic imaging that uses very small amounts of radioactive material. The patient is injected with a liquid that contains the radioactive substance, which collects in the part of the body to be imaged. Sophisticated instruments detect the radioactive substance in the body and process that information into an image.

nurse
A health professional trained to care for people who are ill or disabled.

nutraceutical
A food or dietary supplement that is believed to provide health benefits.

nutrient
A chemical compound (such as protein, fat, carbohydrate, vitamins, or minerals) that make up foods. These compounds are used by the body to function and grow.

nutrition
The taking in and use of food and other nourishing material by the body. Nutrition is a 3-part process. First, food or drink is consumed. Second, the body breaks down the food or drink into nutrients. Third, the nutrients travel through the bloodstream to different parts of the body where they are used as "fuel" and for many other purposes. To give the body proper nutrition, a person has to eat and drink enough of the foods that contain key nutrients.

nutritionist
A health professional with special training in nutrition who can offer help with the choice of foods a person eats and drinks. Also called a dietitian.

nystatin
A drug that treats infections caused by fungi.

O

O(6)-benzylguanine
A drug that may improve the response of cancer cells to chemotherapy.

oat cell cancer
A type of lung cancer in which the cells look like oats when viewed under a microscope. Also called small cell lung cancer.

obese
An abnormally high, unhealthy amount of body fat.

objective improvement
An improvement that can be measured by the health care provider (for example, a decrease in pain can be measured by how much pain medicine the patient is taking).

objective response
A measurable response.

oblimersen
A drug that may kill cancer cells by blocking the production of a protein that makes cancer cells live longer. Also called bcl-2 antisense oligodeoxynucleotide G3139 and augmerosen.

observation
Closely monitoring a patient's condition but withholding treatment until symptoms appear or change. Also called watchful waiting.

observational study
A type of study in which individuals are observed or certain outcomes are measured. No attempt is made to affect the outcome (for example, no treatment is given).

obstruction
Blockage of a passageway.

obtundation  (ob-tun-DAY-shun)
A dulled or reduced level of alertness or consciousness.

occult stage non-small cell lung cancer
Cancer cells are found in sputum (mucus coughed up from the lungs), but no tumor can be found in the lung by imaging or bronchoscopy, or the primary tumor is too small to be assessed.

occupational therapist
A health professional trained to help people who are ill or disabled learn to manage their daily activities.

octreotide
A drug similar to the naturally occurring growth hormone inhibitor somatostatin. Octreotide is used to treat diarrhea and flushing associated with certain types of tumors.

ocular melanoma
A rare cancer of melanocytes (cells that produce the pigment melanin) found in the eye. Also called intraocular melanoma.

off-label
Describes the legal use of a prescription drug to treat a disease or condition for which the drug has not been approved by the US Food and Drug Administration.

ofloxacin
An antibiotic drug used to treat infection. It belongs to the family of drugs called quinolone antibiotics.

OGX-011
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called antisense oligonucleotides.

olbimersen
A drug that may kill cancer cells by blocking the production of a protein that makes cancer cells live longer. Also called bcl-2 antisense oligodeoxynucleotide G3139.

oligoastrocytoma
A rare type of brain tumor made up of two kinds of cells, oligodendrocytes and astrocytes, which are brain cells that nourish and support nerve cells. Also called mixed glioma.

oligodendroglial tumor
A rare, slow-growing tumor that begins in the oligodendrocytes (brain cells that nourish and support nerve cells). Also called an oligodendroglioma.

oligodendroglioma  (OL-ih-go-den-dro-glee-O-ma)
A rare, slow-growing tumor that begins in the oligodendrocytes (brain cells that nourish and support nerve cells). Also called an oligodendroglial tumor.

oltipraz
A drug used in cancer prevention.

omega-3 fatty acid
A type of fat obtained in the diet and involved in immunity.

omentectomy
Surgery to remove part or all of the omentum.

omentum  (oh-MEN-tum)
A fold of the peritoneum (the thin tissue that lines the abdomen) that surrounds the stomach and other organs in the abdomen.

omeprazole
A drug that inhibits gastric acid secretion.

Ommaya reservoir  (o-MY-a REZ-er-vwahr)
A device surgically placed under the scalp and used to deliver anticancer drugs to the fluid surrounding the brain and spinal cord.

oncogene
A gene that normally directs cell growth. If altered, an oncogene can promote or allow the uncontrolled growth of cancer. Alterations can be inherited or caused by an environmental exposure to carcinogens.

oncologist  (on-KOL-o-jist)
A doctor who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment. For example, a radiation oncologist specializes in treating cancer with radiation.

oncology
The study of cancer.

oncology nurse
A nurse who specializes in treating and caring for people who have cancer.

oncology pharmacy specialist
A person who works with an oncologist to prepare anticancer drugs.

oncolysate
An extract made from cancer cells that are infected with a lytic strain of virus. The extract contains both cancer cell proteins and virus proteins. Oncolysates are being studied as cancer vaccines.

oncolysis
The breakdown, or lysis, of a tumor. This can occur by mechanical means, chemicals, or infectious agents such as viruses. Oncolytic viruses do not lyse most normal cells.

oncolytic
Refers to viruses that kill cancer cells more often than they kill normal cells.

Onconase®
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called ribonuclease enzymes. Also called ranpirnase.

ondansetron
A drug that prevents or reduces nausea and vomiting. It belongs to the family of drugs called antiemetics.

onset of action
The length of time it takes for a medicine to start to work.

ONYX-015
A modified cold virus that selectively grows in and destroys certain types of cancer cells and leaves normal cells undamaged.

oophorectomy  (o-o-for-EK-toe-mee)
Surgery to remove one or both ovaries.

open biopsy
A procedure in which a surgical incision (cut) is made through the skin to expose and remove tissues. The biopsy tissue is examined under a microscope by a pathologist. An open biopsy may be done in the doctor’s office or in the hospital, and may use local anesthesia or general anesthesia. A lumpectomy to remove a breast tumor is a type of open biopsy.

open colectomy  (ko-LEK-toe-mee)
An operation to remove all or part of the colon through a long incision made in the wall of the abdomen. When only part of the colon is removed, it is called a partial colectomy.

open label study
A type of study in which both the health providers and the patients are aware of the drug or treatment being given.

operable
Describes a condition that can be treated by surgery.

ophthalmic
Having to do with the eye.

ophthalmoscope  (off-THAL-mo-skope)
A lighted instrument used to examine the inside of the eye, including the retina and the optic nerve.

opioid
A synthetic drug that is used to treat moderate to severe pain. Opioids are similar to opiates such as morphine and codeine.

opportunistic infection
An infection caused by an organism that does not normally cause disease. Opportunistic infections occur in people with weakened immune systems.

optic nerve
The nerve that carries messages from the retina to the brain.

oral
By or having to do with the mouth.

oral surgeon
A dentist with special training in surgery of the mouth and jaw.

orchidectomy
Surgery to remove one or both testicles. Also called orchiectomy.

orchiectomy  (or-kee-EK-toe-mee)
Surgery to remove one or both testicles. Also called orchidectomy.

organ
A part of the body that performs a specific function. For example, the heart is an organ.

organism
A living thing, such as an animal, a plant, a bacterium, or a fungus.

oropharynx  (or-o-FAIR-inks)
The middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils.

OSI-7904L
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called thymidylate synthase inhibitors.

osmolality
The concentration of particles dissolved in a fluid. The osmolality of serum can help diagnose several medical conditions such as dehydration, diabetes, and shock.

osteitis deformans
A chronic condition in which both the breakdown and regrowth of bone are increased. Osteitis deformans occurs most frequently in the pelvic and leg bones, skull, and lower spine. It is most common in older individuals, and may lead to bone pain, deformities, and fractures. Also called Paget's disease of bone.

osteogenic sarcoma
A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young people and affects more males than females. Also called osteosarcoma.

osteolytic
Causing the breakdown of bone.

osteoporosis  (OSS-tee-oh-pa-ROW-sis)
A condition that is characterized by a decrease in bone mass and density, causing bones to become fragile.

osteosarcoma  (AHS-tee-o-sar-KO-ma)
A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young people and affects more males than females. Also called osteogenic sarcoma.

ostomy  (AHS-toe-mee)
An operation to create an opening (a stoma) from an area inside the body to the outside. Colostomy and urostomy are types of ostomies.

otolaryngologist  (OAT-oh-LAR-in-GOL-uh-jist)
A doctor who specializes in treating diseases of the ear, nose, and throat. Also called an ENT (ear, nose, and throat) doctor.

ounce
A measure of weight (one-sixteenth pound) and volume (one-eighth cup).

outpatient
A patient who visits a health care facility for diagnosis or treatment without spending the night. Sometimes called a day patient.

ovarian
Having to do with the ovaries, the female reproductive glands in which the ova (eggs) are formed. The ovaries are located in the pelvis, one on each side of the uterus.

ovarian ablation
Surgery, radiation therapy, or a drug treatment to stop the functioning of the ovaries. Also called ovarian suppression.

ovarian epithelial cancer
Cancer that occurs in the cells lining the ovaries.

ovarian suppression
Surgery, radiation therapy, or a drug treatment to stop the functioning of the ovaries. Also called ovarian ablation.

ovary  (O-va-ree)
One of a pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the pelvis, one on each side of the uterus.

over-the-counter
OTC. A medicine that can be bought without a doctor's order. Examples include some analgesics (pain relievers). Also called nonprescription.

overactive thyroid
Too much thyroid hormone. Symptoms include weight loss, chest pain, cramps, diarrhea, and nervousness. Also called hyperthyroidsm.

overall survival
The percentage of subjects in a study who have survived for a defined period of time. Usually reported as time since diagnosis or treatment. Also called the survival rate.

overexpress
An excess of a particular protein on the surface of a cell.

overgrowth syndrome
A group of genetic disorders in which there is an abnormal increase in the size of the body or a body part that is often noted at birth. Examples of overgrowth syndromes include neurofibromatosis, Sotos syndrome, Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome, Weaver syndrome, Proteus syndrome, Sturge-Weber syndrome, and fragile X syndrome. Many of these syndromes increase the risk of cancer.

overweight
Being too heavy for one’s height. Excess body weight can come from fat, muscle, bone, and/or water retention. Being overweight does not always mean being obese.

ovulation  (ov-yoo-LA-shun)
The release of an egg from an ovary during the menstrual cycle.

oxaliplatin
An anticancer drug that belongs to the family of drugs called platinum compounds.

oxandrolone  (ox-AN-dro-lone)
A drug used to help patients gain weight after injury, chronic infection, or severe illness. It belongs to the family of drugs called anabolic steroids.

OXi-104
An anticancer drug being evaluated in combination with cisplatin.

oxidation
Process in which molecules are split to give products that have unpaired electrons.

oxidative metabolism
A chemical process in which oxygen is used to make energy from carbohydrates (sugars). Also known as aerobic respiration, cell respiration, or aerobic metabolism.

oxidative stress
A condition in which antioxidant levels are lower than normal. Antioxidant levels are usually measured in blood plasma.

P

P-32
A radioactive form of phosphorus used in the treatment of cancer.

p-value
A statistics term. A measure of probability that a difference between groups during an experiment happened by chance. For example, a p-value of .01 (p = .01) means there is a 1 in 100 chance the result occurred by chance. The lower the p-value, the more likely it is that the difference between groups was caused by treatment.

p53 gene
A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.

Pacific valerian
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, garden valerian, Indian valerian, Mexican valerian, garden heliotrope, and Valerianae radix.

pack year
A way to measure the amount a person has smoked over a long period of time. It is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. For example, 1 pack year is equal to smoking 1 pack per day for 1 year, or 2 packs per day for half a year, and so on.

paclitaxel
An anticancer drug that belongs to the family of drugs called mitotic inhibitors.

Paget's disease of bone
A chronic condition in which both the breakdown and regrowth of bone are increased. Paget's disease of bone occurs most frequently in the pelvic and leg bones, skull, and lower spine. It is most common in older individuals, and may lead to bone pain, deformities, and fractures. Also called osteitis deformans.

Paget's disease of the nipple
A form of breast cancer in which the tumor grows from ducts beneath the nipple onto the surface of the nipple. Symptoms commonly include itching and burning and an eczema-like condition around the nipple, sometimes accompanied by oozing or bleeding.

pain threshold
The point at which a person becomes aware of pain.

PALA
An anticancer drug that is being studied to increase the effectiveness of the chemotherapy drug fluorouracil.

palate  (PAL-et)
The roof of the mouth. The front portion is bony (hard palate), and the back portion is muscular (soft palate).

palliative care  (PAL-ee-yuh-tiv)
Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of palliative care is to prevent or treat as early as possible the symptoms of the disease, side effects caused by treatment of the disease, and psychological, social, and spiritual problems related to the disease or its treatment. Also called comfort care, supportive care, and symptom management.

palliative therapy  (PAL-ee-yuh-tiv)
Treatment given to relieve the symptoms and reduce the suffering caused by cancer and other life-threatening diseases. Palliative cancer therapies are given together with other cancer treatments, from the time of diagnosis, through treatment, survivorship, recurrent or advanced disease, and at the end of life.

palmar-plantar erythodysthesia
A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also known as hand-foot syndrome.

palpable disease
A term used to describe cancer that can be felt by touch, usually present in lymph nodes, skin, or other organs of the body such as the liver or colon.

palpation
Examination by pressing on the surface of the body to feel the organs or tissues underneath.

pamidronate
A drug that is used to treat hypercalcemia (too much calcium in the blood) and cancer that has spread to the bones. It belongs to the family of drugs called bisphosphonates.

panacea
A cure-all.

Pancoast's tumor
Non-small cell lung cancer that originates in the upper portion of the lung and extends to other nearby tissues such as the ribs and vertebrae. Also called a pulmonary sulcus tumor.

pancreas
A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.

pancreatectomy  (pan-kree-a-TEK-toe-mee)
Surgery to remove all or part of the pancreas. In a total pancreatectomy, part of the stomach, part of the small intestine, the common bile duct, gallbladder, spleen, and nearby lymph nodes also are removed.

pancreatic
Having to do with the pancreas.

pancreatic cancer
A disease in which malignant (cancer) cells are found in the tissues of the pancreas. Also called exocrine cancer.

pancreatic duct
Part of a system of ducts in the pancreas. Pancreatic juices containing enzymes are released into these ducts and flow into the small intestine.

pancreatic enzyme
A protein secreted by the pancreas that aids in the digestion of food.

pancreatic juice
Fluid made by the pancreas. Pancreatic juices contain proteins called enzymes that aid in digestion.

pancreatitis
Inflammation of the pancreas. Chronic pancreatitis may cause diabetes and problems with digestion. Pain is the primary symptom.

PAP
Prostatic acid phosphatase. An enzyme produced by the prostate. It may be found in increased amounts in men who have prostate cancer.

Pap smear
The collection of cells from the cervix for examination under a microscope. It is used to detect changes that may be cancer or may lead to cancer, and can show noncancerous conditions, such as infection or inflammation. Also called a Pap test.

Pap test
The collection of cells from the cervix for examination under a microscope. It is used to detect changes that may be cancer or may lead to cancer, and can show noncancerous conditions, such as infection or inflammation. Also called a Pap smear.

papillary serous carcinoma
An aggressive cancer that usually affects the uterus/endometrium, peritoneum, or ovary.

papillary thyroid cancer  (PAP-i-lair-ee)
Cancer that develops from cells in the thyroid and forms small finger-like projections. The most common type of thyroid cancer, it grows slowly, is more common in women than in men, and often develops before age 40.

papillary tumor  (PAP-ih-lar-ee TOO-mer)
A tumor shaped like a small mushroom, with its stem attached to the epithelial layer (inner lining) of an organ.

papilledema  (pap-il-eh-DEE-ma)
Swelling around the optic disk, the area where the optic nerve (the nerve that carries messages from the eye to the brain) enters the eyeball. Papilledema occurs when increased brain pressure caused by tumors or other problems results in swelling of the optic nerve.

paracentesis
Insertion of a thin needle or tube into the abdomen to remove fluid from the peritoneal cavity.

parageusia
A bad taste in the mouth. Also called dysgeusia.

paralysis  (pa-RAL-ih-sis)
Loss of ability to move all or part of the body.

paramyxovirus
A type of virus that has hemagglutinin-neuraminidase proteins in the outer coat and RNA as the genetic material. Measles (rubeola) virus, mumps virus, and Newcastle disease virus are paramyxoviruses.

paraneoplastic syndrome  (pair-a-nee-o-PLAS-tik)
A group of symptoms that may develop when substances released by some cancer cells disrupt the normal function of surrounding cells and tissue.

parasite
An animal or a plant that lives on or in an organism of another species and gets nutrients from it. A complete parasite gets all of its nutrients from the host organism, but a semi-parasite gets only some of its nutrients from the host.

parasitic
Having to do with or being a parasite.

parathyroid gland  (pair-a-THIGH-roid)
One of four pea-sized glands found on the thyroid. The parathyroid hormone produced by these glands increases the calcium level in the blood.

parathyroid hormone  (par-a-THI-royd)
A substance made by the parathyroid gland that helps the body store and use calcium. Also called parathormone, parathyrin, or PTH.

parenchyma  (pah-REN-kih-ma)
The essential or functional elements of an organ.

paresthesias
Abnormal touch sensations, such as burning or prickling, that occur without an outside stimulus.

paricalcitol  (par-i-KAL-si-tol)
A substance that is being used to treat overactive parathyroid glands in patients with kidney failure. It is also being studied in the treatment of cancer. Paricalcitol belongs to the family of drugs called vitamin D analogs.

parietal pericardium
The outer layer of the pericardium, which is a thin sac of tissue that surrounds the heart.

Parkinson's disease
A progressive disorder of the nervous system marked by muscle tremors, muscle rigidity, decreased mobility, stooped posture, slow voluntary movements, and a mask-like facial expression.

parotidectomy
Surgery to remove all or part of the parotid gland (a large salivary gland located in front of and just below the ear). In a radical parotidectomy, the entire gland is removed.

paroxetine hydrochloride
An antidepressant drug.

partial cystectomy  (sis-TEK-to-mee)
The removal of the cancer as well as some of the bladder tissue around the tumor. Also called segmental cystectomy.

partial laryngectomy  (PAR-shul lair-in-JEK-tuh-mee)
An operation to remove part of the larynx (voice box).

partial mastectomy  (mas-TEK-toe-mee)
The removal of cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are also taken out. Also called segmental mastectomy.

partial nephrectomy  (neh-FREK-tuh-mee)
Surgery to remove part of one kidney or a kidney tumor, but not an entire kidney.

partial oophorectomy  (o-o-for-EK-toe-mee)
Surgery to remove part of one ovary or part of both ovaries.

partial remission
A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment. Also called partial response.

partial response
A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment.

passive antibody therapy
Treatment with injections of antibodies made in another animal or in the laboratory.

pathologic fracture
A broken bone caused by disease, often by the spread of cancer to the bone.

pathological staging
A method used to determine the stage of cancer. Tissue samples are removed during surgery or a biopsy. The stage is determined based on how the cells in the samples look under a microscope.

pathologist  (pa-THOL-o-jist)
A doctor who identifies diseases by studying cells and tissues under a microscope.

pathology report
The description of cells and tissues made by a pathologist based on microscopic evidence, and sometimes used to make a diagnosis of a disease.

patient advocate
A person who helps a patient work with others who have an effect on the patient's health, including doctors, insurance companies, employers, case managers, and lawyers. A patient advocate helps resolve issues about health care, medical bills, and job discrimination related to a patient's medical condition. Cancer advocacy groups try to raise public awareness about important cancer issues, such as the need for cancer support services, education, and research. Such groups work to bring about change that will help cancer patients and their families.

patient-controlled analgesia
PCA. A method in which the patient controls the amount of pain medicine that is used. When pain relief is needed, the person can receive a preset dose of pain medicine by pressing a button on a computerized pump that is connected to a small tube in the body.

PCA
Patient-controlled analgesia. A method in which the patient controls the amount of pain medicine that is used. When pain relief is needed, the person can receive a preset dose of pain medicine by pressing a button on a computerized pump that is connected to a small tube in the body.

PDQ
Physician Data Query. PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information is available on the Cancer.gov Web site. More specific information about PDQ can be found at http://cancer.gov/cancer_information/pdq/.

peau d'orange
A dimpled condition of the skin of the breast, resembling the skin of an orange, sometimes found in inflammatory breast cancer.

pediatric  (pee-dee-AT-rik)
Having to do with children.

pediatric hematologist
A doctor who specializes in treating blood disorders in children.

pediatric nurse specialist
A registered nurse with an advanced degree in nursing who specializes in the care of children.

pediatric surgeon
A surgeon who specializes in the treatment of children. A surgeon removes or repairs a part of the body by operating on the patient.

pedigree
A record of one's ancestors, offspring, siblings, and their offspring that may be used to determine the pattern of certain genes or disease inheritance within a family.

PEG-interferon alfa-2a
A substance that is used to treat hepatitis C infections, and is being studied in the treatment of cancer. It belongs to the family of drugs called biological response modifiers.

PEG-interferon alfa-2b
An anticancer drug that belongs to the family of drugs called biological response modifiers. PEG-interferon alfa-2b is a cytokine. Also called SCH 54031.

PEG-MGDF
A synthetic form of a protein that is normally made in the body to regulate the production of platelets.

pegaspargase
A modified form of asparaginase, an anticancer drug that belongs to the family of drugs derived from enzymes.

pegfilgrastim
A substance that is being studied for its ability to increase numbers of white blood cells in people who are receiving chemotherapy. It belongs to the family of drugs called colony-stimulating factors. Also called filgrastim-SD/01.

PEITC
Phenethyl isothiocyanate. A naturally occurring compound found in some cruciferous vegetables. It is being studied as an agent to prevent cancer.

peldesine
A substance that is being studied for the treatment of cancer.

pelvic
Having to do with the pelvis (the lower part of the abdomen located between the hip bones).

pelvic exam
A physical examination of the vagina, cervix, uterus, fallopian tubes, ovaries, and rectum.

pelvic exenteration
Surgery to remove the lower colon, rectum, and bladder, and create openings (stomata) through which urine and stool are passed out of the body. In women, the cervix, vagina, ovaries, and nearby lymph nodes are also removed.

pelvic lymphadenectomy  (lim-FAD-eh-NEK-tah-me)
Surgery to remove lymph nodes in the pelvis for examination under a microscope to see if they contain cancer.

pelvis
The lower part of the abdomen, located between the hip bones.

pemetrexed disodium
An anticancer drug that belongs to the family of drugs called enzyme inhibitors. Also called LY231514.

penclomedine
An anticancer drug that belongs to the family of drugs called alkylating agents.

penicillamine
A drug that removes copper from the body and is used to treat diseases in which there is an excess of this metal. It is also being studied as a possible angiogenesis inhibitor in brain tumors.

penicillin
An antibiotic drug used to treat infection.

penile implant
A firm rod or inflatable device that is placed in the penis during a surgical procedure. The implant makes it possible to have and keep an erection. Penile implants are used to treat erectile dysfunction or impotence.

penis
An external male reproductive organ. It contains a tube called the urethra, which carries semen and urine to the outside of the body.

pentetic acid calcium
A drug that protects healthy tissues from the toxic effects of anticancer drugs.

pentosan polysulfate
A drug used to relieve pain or discomfort associated with chronic inflammation of the bladder. It is also being evaluated for its protective effects on the gastrointestinal tract in people undergoing radiation therapy.

pentostatin
An anticancer drug that belongs to the family of drugs called antimetabolites.

pentoxifylline
A drug used to prevent blood clotting and as a treatment that may help decrease weight loss in people with cancer.

peptide
Any compound consisting of two or more amino acids, the building blocks of proteins.

peptide 946
A protein that causes white blood cells to recognize and destroy melanoma cells.

percutaneous ethanol injection  (per-kyoo-TAY-nee-us)
An injection of ethanol (alcohol) through the skin directly into the tumor to kill cancer cells.

percutaneous transhepatic biliary drainage
A procedure to drain bile to relieve pressure in the bile ducts caused by a blockage. An x-ray of the liver and bile ducts locates the blockage of bile flow. Images made by ultrasound guide placement of a stent (tube), which remains in the liver. Bile drains through the stent into the small intestine or into a collection bag outside the body. This procedure may relieve jaundice before surgery. Also called percutaneous transhepatic cholangiodrainage (PTCD).

percutaneous transhepatic cholangiodrainage
PTCD. A procedure to drain bile to relieve pressure in the bile ducts caused by a blockage. An x-ray of the liver and bile ducts locates the blockage of bile flow. Images made by ultrasound guide placement of a stent (tube), which remains in the liver. Bile drains through the stent into the small intestine or into a collection bag outside the body. This procedure may relieve jaundice before surgery. Also called percutaneous transhepatic biliary drainage.

percutaneous transhepatic cholangiography  (per-kyoo-TAY-nee-us trans-heh-PAT-ik ko-LAN-jee-AH-gra-fee)
PTC. A procedure to x-ray the hepatic and common bile ducts. A contrasting agent is injected into the liver or bile duct, and the ducts are then x-rayed to find the point of obstruction.

performance status
A measure of how well a patient is able to perform ordinary tasks and carry out daily activities.

perfusion
Bathing an organ or tissue with a fluid. In regional perfusion, a specific area of the body (usually an arm or a leg) receives high doses of anticancer drugs through a blood vessel. Such a procedure is performed to treat cancer that has not spread.

perfusion magnetic resonance imaging
A type of magnetic resonance imaging (MRI) used to check the flow of blood to normal tissue and diseased tissue.

pericardial effusion
An abnormal collection of fluid inside the sac that covers the heart.

perifosine
An anticancer drug that belongs to the family of drugs called alkylphospholipids.

perillyl alcohol
A drug used in cancer prevention that belongs to the family of plant drugs called monoterpenes.

perimenopausal
The time of a woman's life when menstrual periods become irregular. Refers to the time near menopause.

perineal colostomy
An opening made surgically to allow the colon to exit the body through the perineum (the area of the body between the anus and the vulva in females, and between the anus and the scrotum in males). A colostomy provides a new path for waste material to leave the body after part of the colon has been removed.

perineal prostatectomy  (peh-rih-NEE-al pros-ta-TEK-toe-mee)
Surgery to remove the prostate through an incision made between the scrotum and the anus.

perineum
The area of the body between the anus and the vulva in females, and between the anus and the scrotum in males.

perineural  (pear-ih-NOOR-al)
Around a nerve or group of nerves.

perioperative
Around the time of surgery; usually lasts from the time of going into the hospital or doctor's office for surgery until the time the patient goes home.

peripheral blood
Blood circulating throughout the body.

peripheral blood lymphocyte therapy
A treatment for Epstein-Barr virus infection or overgrowth of white blood cells (lymphocytes) after an organ or bone marrow transplant. Specific lymphocytes from a sibling donor are infused into the patient to try and reverse these conditions.

peripheral neuropathy
A condition of the nervous system that causes numbness, tingling, burning or weakness. It usually begins in the hands or feet, and can be caused by certain anticancer drugs.

peripheral primitive neuroectodermal tumor  (...NOO-ro-ek-toe-DER-mul...)
pPNET. A type of cancer that forms in bone or soft tissue. Also called Ewing's sarcoma.

peripheral stem cell
An immature cell found circulating in the bloodstream. New blood cells develop from peripheral stem cells.

peripheral stem cell support  (per-IF-er-al)
A method of replacing blood-forming cells destroyed by cancer treatment. Immature blood cells (stem cells) in the circulating blood that are similar to those in the bone marrow are given to the patient after treatment. This helps the bone marrow recover and continue producing healthy blood cells. Transplantation may be autologous (an individual's own blood cells saved earlier), allogeneic (blood cells donated by someone else), or syngeneic (blood cells donated by an identical twin). Also called peripheral stem cell transplantation.

peripheral stem cell transplantation  (per-IF-er-al)
A method of replacing blood-forming cells destroyed by cancer treatment. Immature blood cells (stem cells) in the circulating blood that are similar to those in the bone marrow are given to the patient after treatment. This helps the bone marrow recover and continue producing healthy blood cells. Transplantation may be autologous (an individual's own blood cells saved earlier), allogeneic (blood cells donated by someone else), or syngeneic (blood cells donated by an identical twin). Also called peripheral stem cell support.

peristalsis  (pair-ih-STAL-sis)
The rippling motion of muscles in the intestine or other tubular organs characterized by the alternate contraction and relaxation of the muscles that propel the contents onward.

peritoneal
Having to do with the peritoneum (the tissue that lines the abdominal wall and covers most of the organs in the abdomen).

peritoneal cavity
The space within the abdomen that contains the intestines, the stomach, and the liver. It is bound by thin membranes.

peritoneal perfusion
A method of delivering fluids and drugs directly to tumors in the peritoneal cavity.

peritoneum  (PAIR-ih-toe-NEE-um)
The tissue that lines the abdominal wall and covers most of the organs in the abdomen.

peritonitis
Inflammation of the peritoneum (tissue that lines the abdominal wall and covers most of the organs in the abdomen). Peritonitis can result from infection, injury, or certain diseases. Symptoms may include swelling of the abdomen, severe pain, and weight loss.

pernicious anemia  (per-NISH-us a-NEE-mee-a)
A type of anemia (low red blood cell count) caused by the body's inability to absorb vitamin B12.

pertuzumab  (per-TOO-zoo-mab)
A monoclonal antibody that is being studied in the treatment of cancer. Monoclonal antibodies are produced in the laboratory and can locate and bind to cancer cells.

PET scan
Positron emission tomography scan. A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body.

petechiae  (peh-TEH-kee-a)
Pinpoint, unraised, round red spots under the skin caused by bleeding.

Peutz-Jeghers syndrome
PJS. A genetic disorder in which polyps form in the intestine and dark spots appear on the mouth and fingers. Having PJS increases the risk of developing gastrointestinal and many other types of cancer.

phagocyte
An immune system cell that can surround and kill microorganisms and remove dead cells. Phagocytes include macrophages.

phantom limb pain
The sensation of pain or other unpleasant feelings in the place of a missing (phantom) limb.

pharmacokinetics
The activity of drugs in the body over a period of time, including the processes by which drugs are absorbed, distributed in the body, localized in the tissues, and excreted.

pharmacopoeia
A book describing chemicals, drugs, and other substances and how they are used as medicines. It is prepared by a recognized authority.

pharynx  (FAIR-inks)
The hollow tube about 5 inches long that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach).

phase I trial
The first step in testing a new treatment in humans. These studies test the best way to give a new treatment (for example, by mouth, intravenous infusion, or injection) and the best dose. The dose is usually increased a little at a time in order to find the highest dose that does not cause harmful side effects. Because little is known about the possible risks and benefits of the treatments being tested, phase I trials usually include only a small number of patients who have not been helped by other treatments.

phase I/II trial
A trial to study the safety, dosage levels, and response to a new treatment.

phase II trial
A study to test whether a new treatment has an anticancer effect (for example, whether it shrinks a tumor or improves blood test results) and whether it works against a certain type of cancer.

phase II/III trial
A trial to study response to a new treatment and the effectiveness of the treatment compared with the standard treatment regimen.

phase III trial
A study to compare the results of people taking a new treatment with the results of people taking the standard treatment (for example, which group has better survival rates or fewer side effects). In most cases, studies move into phase III only after a treatment seems to work in phases I and II. Phase III trials may include hundreds of people.

phase IV trial
After a treatment has been approved and is being marketed, it is studied in a phase IV trial to evaluate side effects that were not apparent in the phase III trial. Thousands of people are involved in a phase IV trial.

phenethyl isothiocyanate
PEITC. A naturally occurring compound found in some cruciferous vegetables. It is being studied as an agent to prevent cancer.

phenobarbital
A sedative/anticonvulsant barbiturate that has been used to treat diarrhea and to increase the antitumor effect of other therapies.

phenoxodiol
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called signal transduction inhibitors.

phenylacetate
A drug being studied in the treatment of cancer.

phenylbutyrate
An anticancer drug that belongs to the family of drugs called differentiating agents.

pheochromocytoma
A tumor of the adrenal gland that causes it to produce too much adrenaline. Pheochromocytomas are usually benign (noncancerous), but can cause dangerously high blood pressure and other symptoms, including pounding headaches, heart palpitations, flushing of the face, nausea, and vomiting.

pheresis  (fer-E-sis)
A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to the donor. Also called apheresis.

Philadelphia chromosome
An abnormality of chromosome 22 in which part of chromosome 9 is transferred to it. Bone marrow cells that contain the Philadelphia chromosome are often found in chronic myelogenous leukemia.

phlebotomy
The puncture of a vein with a needle for the purpose of drawing blood. Also called venipuncture.

phosphorous  (FOS-for-us)
Having to do with or containing the element phosphorus.

phosphorus  (FOS-for-us)
A nonmetallic element that is found in the blood, muscles, nerves, bones, and teeth and is a component of adenosine triphosphate (ATP; the primary energy source for the body's cells).

phosphorus-32
A radioactive form of phosphorus used in the treatment of cancer. It is also used to help locate areas of DNA damage.

photoactivity
The effect produced when certain substances are exposed to light. In cancer treatment, some drugs become active when exposed to light and are then able to kill tumor cells.

photodynamic therapy  (foe-toe-dye-NAM-ik)
Treatment with drugs that become active when exposed to light. These drugs kill cancer cells.

photofrin
A drug used in photodynamic therapy that is absorbed by tumor cells. When absorbed by cancer cells and exposed to light, photofrin becomes active and kills the cancer cells.

photopheresis
A procedure in which blood is treated outside the body, with ultraviolet light and drugs that become active when exposed to light, and then returned to the body. It is being studied as a treatment for some blood and bone marrow diseases and graft-versus-host disease (GVHD). Also called extracorporeal photophoresis.

photophobia
A condition in which the eyes are more sensitive to light than normal.

photosensitizer
A drug used in photodynamic therapy. When absorbed by cancer cells and exposed to light, the drug becomes active and kills the cancer cells.

phyllodes tumor
A type of tumor found in breast tissue. It is often large and bulky and grows quickly. It is usually benign (not cancer), but may be malignant (cancer). Also called cystosarcoma phyllodes.

physical examination
An exam of the body to check for general signs of disease.

physical therapist
A health professional who teaches exercises and physical activities that help condition muscles and restore strength and movement.

physical therapy
The use of exercises and physical activities to help condition muscles and restore strength and movement. For example, physical therapy can be used to restore arm and shoulder movement and build back strength after breast cancer surgery.

Physician Data Query
PDQ. The Physician Data Query is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information is available on the Cancer.gov Web site. More specific information about PDQ can be found at http://cancer.gov/cancer_information/pdq/.

physiologic
Having to do with the functions of the body. When used in the phrase "physiologic age," it refers to an age assigned by general health, as opposed to calendar age.

phytic acid
A substance that has been studied as a treatment for cancer. Phytic acid is found in large amounts in cereals and legumes. Also known as inositol hexaphosphate.

phytochemical
A chemical found in plants. Many phytochemicals are thought to reduce a person's risk of getting cancer.

phytoestrogen
An estrogen-like substance found in some plants and plant products. Phytoestrogens may have anticancer effects.

phytosterol
A plant-based compound that can compete with dietary cholesterol to be absorbed by the intestines, resulting in lower blood cholesterol levels. Phytosterols may have some effect in cancer prevention. Also called plant sterol.

PI-88
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called antiangiogenesis agents.

pigment
A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.

pilocarpine
A drug used to increase salivation in people who have dry mouth caused by opioids or radiation therapy. Pilocarpine belongs to the family of drugs called alkaloids.

pilocytic  (PI-lo-SIT-ik)
Made up of cells that look like fibers when viewed under a microscope.

pilot study
The initial study examining a new method or treatment.

pineal body
A tiny organ in the cerebrum that produces melatonin. Also called pineal gland or pineal organ.

pineal gland  (PIN-ee-al)
A tiny organ in the cerebrum that produces melatonin. Also called pineal body or pineal organ.

pineal organ
A tiny organ in the cerebrum that produces melatonin. Also called pineal body or pineal gland.

pineal region tumor  (PIN-ee-al...)
A type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

pineoblastoma  (PIN-ee-o-blas-TOE-ma)
A fast growing type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

pineocytoma  (PIN-ee-o-sye-TOE-ma)
A slow growing type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

piperacillin-tazobactam
A combination of drugs used to fight infections in people who have cancer. Piperacillin is a synthetic penicillin; tazobactam enhances the effectiveness of piperacillin.

pirfenidone
A substance that is being studied in the prevention and treatment of scar tissue caused by radiation therapy. It belongs to the family of drugs called anti-inflammatory agents.

piritrexim
An anticancer drug.

pituitary gland  (pih-TOO-ih-tair-ee)
The main endocrine gland. It produces hormones that control other glands and many body functions, especially growth.

pixantrone
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called antitumor antibiotics. Also called BBR 2778.

PJS
Peutz-Jeghers syndrome. A genetic disorder in which polyps form in the intestine and dark spots appear on the mouth and fingers. Having PJS increases the risk of developing gastrointestinal and many other types of cancer.

PKC412
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called protein kinase C (PKC) inhibitors.

placebo
An inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo.

placebo-controlled
Refers to a clinical study in which the control patients receive a placebo.

placenta
The organ that nourishes the developing fetus in the uterus.

placental blood transplantation
The transfer of blood from a placenta to an individual whose own blood production system is suppressed. Placental blood contains high levels of stem cells needed to produce new blood cells. It is being studied in the treatment of cancer and severe blood disorders such as aplastic anemia. Also called umbilical cord blood transplant.

plant sterol
A plant-based compound that can compete with dietary cholesterol to be absorbed by the intestines, resulting in lower blood cholesterol levels. Plant sterols may have some effect in cancer prevention. Also called phytosterol.

plasma  (PLAS-ma)
The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.

plasma cell
A type of white blood cell that produces antibodies.

plasma membrane
The outer membrane of a cell.

plasmacytic
Having to do with plasma cells (a type of white blood cells).

plasmacytoma  (PLAS-ma-sye-TOE-ma)
Cancer of the plasma cells (white blood cells that produce antibodies) that may turn into multiple myeloma.

plasmapheresis  (plas-ma-fer-EE-sis)
The process of separating certain cells from the plasma in the blood by a machine; only the cells are returned to the person. Plasmapheresis can be used to remove excess antibodies from the blood.

plastic surgeon
A surgeon who specializes in reducing scarring or disfigurement that may occur as a result of accidents, birth defects, or treatment for diseases.

plastic surgery
An operation that restores or improves the appearance of body structures.

platelet  (PLAYT-let)
A type of blood cell that helps prevent bleeding by causing blood clots to form. Also called a thrombocyte.

platinum
A metal that is an important component of some anticancer drugs, such as cisplatin and carboplatin.

Plenaxis
A drug used to reduce the amount of testosterone made in patients with advanced symptomatic prostate cancer for which no other treatment options are available. It belongs to the family of drugs called gonadotropin-releasing hormone (GnRH) antagonists. Also called abarelix.

pleomorphic
Occurring in various distinct forms. In terms of cells, having variation in the size and shape of cells or their nuclei.

pleura  (PLOOR-a)
A thin layer of tissue covering the lungs and lining the interior wall of the chest cavity. It protects and cushions the lungs. This tissue secretes a small amount of fluid that acts as a lubricant, allowing the lungs to move smoothly in the chest cavity while breathing.

pleural cavity
The space enclosed by the pleura, which is a thin layer of tissue that covers the lungs and lines the interior wall of the chest cavity.

pleural effusion
An abnormal collection of fluid between the thin layers of tissue (pleura) lining the lung and the wall of the chest cavity.

pleurodesis  (PLOO-ro-DEE-sis)
A medical procedure that uses chemicals or drugs to cause inflammation and adhesion between the layers of the pleura (the tissue that covers the lungs and lines the interior wall of the chest cavity). This prevents the buildup of fluid in the pleural cavity. It is used as a treatment for severe pleural effusion.

plexiform neurofibroma
A nerve that has become thick and misshapen due to the abnormal growth of cells and tissues that cover the nerve.

plexopathy  (pleks-AH-pah-thee)
A disorder affecting a network of nerves, blood vessels, or lymph vessels.

ploidy  (PLOY-dee)
The number of sets of chromosomes in a cell or an organism. For example, haploid means one set and diploid means two sets.

pluripotent
Able to mature or develop in any of several ways.

pluripotent stem cell
A cell that is able to develop into several different types of cells or tissues in the body.

pM-81 monoclonal antibody
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

pneumatic larynx  (noo-MAT-ik LAIR-inks)
A device that is used to help a person talk after a laryngectomy. It uses air to produce a humming sound, which is converted to speech by movement of the lips, tongue, or glottis.

pneumonectomy  (noo-mo-NEK-toe-mee)
An operation to remove an entire lung.

pneumonia  (noo-MONE-ya)
An inflammatory infection that occurs in the lung.

PNU 166148
A drug that belongs to the family of drugs called topoisomerase inhibitors. It is being studied for its ability to treat cancer.

PNU-93914
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called topoisomerase inhibitors.

polifeprosan 20 carmustine implant
A biodegradable wafer that is used to deliver the anticancer drug carmustine directly into a brain tumor site after the tumor has been removed by surgery. Also called Gliadel Wafers.

poly-ICLC
A substance that is being studied as a treatment for cancer and as an immune system stimulant. It is made in the laboratory by combining the nucleic acid RNA with the chemicals poly-L-lysine and carboxymethyl cellulose.

polyglutamate camptothecin
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called camptothecins. Also called CT-2106.

polyglutamate paclitaxel
A protein that can be linked to a chemotherapy drug to deliver the drug directly to the tumor with fewer side effects. It is being studied as a treatment for cancer. Also called CT-2103.

polymerase chain reaction
PCR. A laboratory method used to make many copies of a specific DNA sequence.

polymorphism
A common variation or mutation in DNA.

polyneuritis
Inflammation of several peripheral nerves at the same time.

polyp  (POL-ip)
A growth that protrudes from a mucous membrane.

polypectomy  (POL-i-PEK-tuh-mee)
Surgery to remove a polyp.

polyphenol
A substance that is found in many plants and gives some flowers, fruits, and vegetables their color. Polyphenols have antioxidant activity.

Polyphenon® E
A substance that is being studied in the prevention of cancer. It is made from decaffeinated green tea, and contains chemicals called catechins, which are antioxidants.

polyposis
The development of numerous polyps (growths that protrude from a mucous membrane).

polysaccharide
A type of carbohydrate. It contains sugar molecules that are linked together chemically.

pomegranate
Punica granatum. A subtropical shrub or tree. Juice from the fruit may contain substances that decrease or slow the rise of prostate-specific antigen (PSA) levels. It is being studied for its ability to delay or prevent recurrent prostate cancer.

pons
Part of the central nervous system, located at the base of the brain, between the medulla oblongata and the midbrain. It is part of the brainstem.

pontine
Having to do with the pons (part of the central nervous system, located at the base of the brain, between the medulla oblongata and the midbrain).

porfimer sodium
An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents.

porfiromycin
An anticancer drug that belongs to the family of drugs called anticancer antibiotics.

port
An implanted device through which blood may be withdrawn and drugs may be infused without repeated needle sticks. Also called a port-a-cath.

port-a-cath
An implanted device through which blood may be withdrawn and drugs may be infused without repeated needle sticks. Also called a port.

portal vein
A blood vessel that carries blood from the digestive organs and the spleen to the liver.

positive axillary lymph node
A lymph node in the area of the armpit (axilla) to which cancer has spread. This spread is determined by surgically removing some of the lymph nodes and examining them under a microscope to see whether cancer cells are present.

positive test result
A test result that reveals the presence of a specific disease or condition for which the test is being done.

positron emission tomography scan
PET scan. A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body.

postmenopausal
Refers to the time after menopause. Menopause is the time in a woman's life when menstrual periods stop permanently; also called "change of life."

postmortem
After death. Often used to describe an autopsy.

postoperative
After surgery.

postprandial
After a meal.

postremission therapy
Anticancer drugs given to kill cancer cells that survive after remission induction therapy.

potassium  (po-TASS-ee-um)
A metallic element that is important in body functions such as regulation of blood pressure and of water content in cells, transmission of nerve impulses, digestion, muscle contraction, and heartbeat.

potassium hydroxide
A toxic and highly corrosive chemical used to make soap, in bleaching, and as a paint remover. It is used in small amounts as a food additive and in the preparation of some drugs.

potentiation
In medicine, the effect of increasing the potency or effectiveness of a drug or other treatment.

PR+
Progesterone receptor positive. Breast cancer cells that have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR+ need the hormone progesterone to grow and will usually respond to hormonal therapy.

PR-
Progesterone receptor negative. Breast cancer cells that do not have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR- do not need the hormone progesterone to grow and usually do not respond to hormonal therapy.

precancerous  (pre-KAN-ser-us)
A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

precancerous dermatitis
A skin disease marked by scaly or thickened patches on the skin, and often caused by prolonged exposure to arsenic. The patches often occur on sunexposed areas of the skin and in older white men. These patches may become malignant (cancerous). Also called Bowen's disease or precancerous dermatosis.

precancerous dermatosis
A skin disease marked by scaly or thickened patches on the skin, and often caused by prolonged exposure to arsenic. The patches often occur on sunexposed areas of the skin and in older white men. These patches may become malignant (cancerous). Also called Bowen's disease or precancerous dermatitis.

precancerous polyps
Growths that protrude from a mucous membrane. Precancerous polyps may (or are likely to) become cancer.

preclinical study
Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

predictive factor  (pre-DIK-tiv)
A situation or condition that may increase a person's risk of developing a certain disease or disorder.

prednisolone
A synthetic corticosteroid used in the treatment of blood cell cancers (leukemias) and lymph system cancers (lymphomas).

prednisone
Belongs to the family of drugs called steroids and is used to treat several types of cancer and other disorders. Prednisone also inhibits the body's immune response.

preleukemia  (PREE-loo-KEE-mee-a)
A disease in which the bone marrow does not function normally. Also called myelodysplastic syndrome or smoldering leukemia.

premalignant
A term used to describe a condition that may (or is likely to) become cancer. Also called precancerous.

premenopausal
Refers to the time before menopause. Menopause is the time of life when a women's menstrual periods stop permanently; also called "change of life."

prescription
A doctor's order for medicine or another intervention.

pretracheal space
The area in front of the trachea (windpipe).

prevascular space
The area in the front part of the chest between the lungs. Also called anterior mediastinum.

preventive
Used to prevent disease.

preventive mastectomy
Surgery to remove one or both breasts in order to decrease the risk of developing breast cancer. Also called prophylactic mastectomy.

primary care doctor
A doctor who manages a person's health care over time. A primary care doctor is able to give a wide range of care, including prevention and treatment, can discuss cancer treatment choices, and can refer a patient to a specialist.

primary central nervous system lymphoma
Cancer that arises in the lymphoid tissue found in the central nervous system (CNS). The CNS includes the brain and spinal cord.

primary endpoint
The main result that is measured at the end of a study to see if a given treatment worked (e.g., the number of deaths or the difference in survival between the treatment group and the control group). What the primary endpoint will be is decided before the study begins.

primary myelofibrosis
A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and blood is made in organs such as the liver and the spleen, instead of in the bone marrow. This disease is marked by an enlarged spleen and progressive anemia. Also called chronic idiopathic myelofibrosis, agnogenic myeloid metaplasia, myelosclerosis with myeloid metaplasia, and idiopathic myelofibrosis.

primary tumor
The original tumor.

prinomastat
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called angiogenesis inhibitors. Prinomastat is a matrix metalloproteinase inhibitor. Also called AG3340.

pro-oxidant
A substance that can produce oxygen byproducts of metabolism that can cause damage to cells.

probenecid
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called antibiotic therapy adjuncts.

procarbazine
An anticancer drug that belongs to the family of drugs called alkylating agents.

prochlorperazine  (pro-klor-PAIR-a-zeen)
A drug that prevents or reduces nausea and vomiting. It belongs to the family of drugs called antiemetics.

proctoscopy  (prok-TOS -ko-pee)
An examination of the rectum using a thin, lighted tube called a proctoscope.

proctosigmoidoscopy  (PROK-toe-sig-moid-OSS-ko-pee)
An examination of the rectum and the lower part of the colon using a thin, lighted tube called a sigmoidoscope.

progeny
Offspring; the product of reproduction or replication.

progesterone  (pro-JES-ter-own)
A female hormone.

progesterone receptor negative  (PR-)
PR-. Breast cancer cells that do not have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR- do not need the hormone progesterone to grow and usually do not respond to hormonal therapy.

progesterone receptor positive  (PR+)
PR+. Breast cancer cells that have a protein (receptor molecule) to which progesterone will attach. Breast cancer cells that are PR+ need the hormone progesterone to grow and will usually respond to hormonal therapy.

progesterone receptor test
A lab test to determine if breast cancer cells have progesterone receptors. If the cells have progesterone receptors, they may depend on progesterone for growth. This information can influence how the breast cancer is treated.

progestin  (pro-JES-tin)
Any natural or laboratory-made substance that has some or all of the biologic effects of progesterone, a female hormone.

prognosis  (prog-NO-sis)
The likely outcome or course of a disease; the chance of recovery or recurrence.

prognostic factor  (prog-NOS-tik)
A situation or condition, or a characteristic of a patient, that can be used to estimate the chance of recovery from a disease or the chance of the disease recurring (coming back).

progression
Increase in the size of a tumor or spread of cancer in the body.

progression-free survival
One type of measurement that can be used in a clinical study or trial to help determine whether a new treatment is effective. It refers to the probability that a patient will remain alive, without the disease getting worse.

progressive disease
Cancer that is increasing in scope or severity.

proliferating
Multiplying or increasing in number. In biology, cell proliferation occurs by a process known as cell division.

proliferative index
A measure of the number of cells in a tumor that are dividing (proliferating). May be used with the S-phase fraction to give a more complete understanding of how fast a tumor is growing.

prolymphocytic leukemia
PLL. A type of chronic lymphocyctic leukemia (CLL), in which too many immature white blood cells (prolymphocytes) are found in the blood and bone marrow. PLL usually progresses more rapidly than classic CLL.

promegapoietin
A colony-stimulating factor that stimulates the production of blood cells, especially platelets; it is given during chemotherapy to increase blood cell regeneration. Promegapoietin is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents.

promyelocytic leukemia
A type of acute myeloid leukemia, a quickly progressing disease in which too many immature blood-forming cells are found in the blood and bone marrow.

prophylactic
In medicine, something that prevents or protects.

prophylactic cranial irradiation  (pro-fih-LAK-tik KRAY-nee-ul ir-ray-dee-AY-shun)
Radiation therapy to the head to reduce the risk that cancer will spread to the brain.

prophylactic mastectomy  (pro-fi-LAK-tik mas-TEK-toe-mee)
Surgery to remove one or both breasts in order to decrease the risk of developing breast cancer. Also called preventive mastectomy.

prophylactic oophorectomy  (pro-fi-LAK-tik o-o-for-EK-toe-mee)
Surgery intended to reduce the risk of ovarian cancer by removing the ovaries before disease develops.

prophylactic surgery
Surgery to remove an organ or gland that shows no signs of cancer, in an attempt to prevent development of cancer of that organ or gland. Prophylactic surgery is sometimes chosen by people who know they are at high risk for developing cancer.

prophylaxis
An attempt to prevent disease.

prospective
In medicine, a study or clinical trial in which participants are identified and then followed forward in time.

prospective cohort study
A research study that follows over time groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) and compares them for a particular outcome (such as lung cancer).

Prost 30 monoclonal antibody
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

prostate  (PROS-tate)
A gland in the male reproductive system just below the bladder. The prostate surrounds part of the urethra (the canal that empties the bladder) and produces a fluid that forms part of semen.

prostate-specific antigen
PSA. A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.

prostate-specific antigen test
A blood test that measures the level of prostate-specific antigen (PSA), a substance produced by the prostate and some other tissues in the body. Increased levels of PSA may be a sign of prostate cancer.

prostatectomy  (pros-ta-TEK-toe-mee)
An operation to remove part or all of the prostate. Radical (or total) prostatectomy is the removal of the entire prostate and some of the tissue around it.

prostatic acid phosphatase  (FOS-fa-tays)
PAP. An enzyme produced by the prostate. It may be found in increased amounts in men who have prostate cancer.

prostatic intraepithelial neoplasia  (pros-TAT-ik in-tra-eh-pih-THEEL-ee-ul NEE-o-play-zha)
PIN. Noncancerous growth of the cells lining the internal and external surfaces of the prostate gland. It is an important sign that prostate cancer may develop.

prostatitis  (PROS-tah-TITE-is)
Inflammation of the prostate gland.

prosthesis  (pros-THEE-sis)
An artificial replacement of a part of the body.

prosthodontist  (pros-tho-DON-tist)
A dentist with special training in making replacements for missing teeth or other structures of the oral cavity to restore an individual's appearance, comfort, or health.

protease inhibitor
A compound that interferes with the ability of certain enzymes to break down proteins. Some protease inhibitors can keep a virus from making copies of itself (for example, AIDS virus protease inhibitors), and some can prevent cancer cells from spreading.

protein  (PRO-teen)
A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

protein kinase C
PKC. A substance that is being studied in the treatment of cancer. PKC is an enzyme found throughout the body's tissues and organs. There are several forms of PKC that are involved in many cellular functions.

proteoglycan
A molecule that contains both protein and glycosaminoglycans, which are a type of polysaccharide. Proteoglycans are found in cartilage and other connective tissues.

proteomic profile
An evaluation of proteins in a sample of blood. This may help detect early cancer or cancer recurrence, or help predict response to treatment.

proteomics
The study of the structure and function of proteins, including the way they work and interact with each other inside cells.

protocol
An action plan for a clinical trial. The plan states what the study will do, how, and why. It explains how many people will be in it, who is eligible to participate, what study agents or other interventions they will be given, what tests they will receive and how often, and what information will be gathered.

proton
A small, positively charged particle of matter found in the atoms of all elements. Streams of protons generated by special equipment can be used for radiation treatment.

proton beam radiation therapy  (…ray-dee-AY-shun…)
A type of radiation therapy that uses protons generated by a special machine. A proton is a type of high-energy radiation that is different from an x-ray.

proton magnetic resonance spectroscopic imaging
A noninvasive imaging method that provides information about cellular activity (metabolic information). It is used along with magnetic resonance imaging (MRI) which provides information about the shape and size of the tumor (spacial information). Also called magnetic resonance spectroscopic imaging and 1H-nuclear magnetic resonance spectroscopic imaging.

protozoal
Having to do with the simplest organisms in the animal kingdom. Protozoa are single-cell organisms, such as ameba, and are different from bacteria, which are not members of the animal kingdom. Some protozoa can be seen without a microscope.

proximal
In medicine, refers to a part of the body that is closer to the center of the body than another part. For example, the knee is proximal to the toes. The opposite is distal.

PS-341
A drug that is being studied as a treatment for cancer. It belongs to the family of drugs called dipeptidyl boronic acids. Also called bortezomib.

PSA
Prostate-specific antigen. A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.

psammoma body  (sam-O-ma)
A structure found in some benign (noncancerous) or malignant (cancerous) tumor cells. Psammoma bodies look like hardened concentric rings when viewed under a microscope. They can be a sign of chronic inflammation.

PSC 833
A drug that belongs to the family of drugs called cyclosporine analogs. It is used with chemotherapy to prevent or overcome the resistance of tumor cells to some anticancer drugs.

pseudomyxoma peritonei  (SOO-doe-mix-O-ma PAIR-ih-TOE-nee-I)
A build-up of mucus in the peritoneal cavity. The mucus may come from ruptured ovarian cysts, the appendix, or from other abdominal tissues, and mucus-secreting cells may attach to the peritoneal lining and continue to secrete mucus.

psoralen
A substance that binds to the DNA in cells and stops them from multiplying. It is being studied in the treatment of graft-versus-host disease and is used in the treatment of psoriasis and vitiligo.

psoriasis
A chronic disease of the skin marked by red patches covered with white scales.

psychologist
A specialist who can talk with patients and their families about emotional and personal matters, and can help them make decisions.

PTC
Percutaneous transhepatic cholangiography (per-kyoo-TAN-ee-us trans-heh-PAT-ik ko-LAN-jee-AH-gra-fee). A procedure to x-ray the hepatic and common bile ducts. A contrasting agent is injected into the liver or bile duct, and the ducts are then x-rayed to find the point of obstruction.

PTCD
Percutaneous transhepatic cholangiodrainage. A procedure to drain bile to relieve pressure in the bile ducts caused by a blockage. An x-ray of the liver and bile ducts locates the blockage of bile flow. Images made by ultrasound guide placement of a stent (tube), which remains in the liver. Bile drains through the stent into the small intestine or into a collection bag outside the body. This procedure may relieve jaundice before surgery. Also called percutaneous transhepatic biliary drainage.

PTK787/ZK 222584
An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors.

ptosis
Drooping of the upper eyelid.

pulmonary
Relating to the lungs.

pulmonary sulcus tumor
Non-small cell lung cancer that originates in the upper portion of the lung and extends to other nearby tissues such as the ribs and vertebrae. Also called a Pancoast tumor.

pump
A device that is used to deliver a precise amount of drug at a specific rate.

purple clover
Trifolium pratense. A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called red clover and wild clover.

PV701
A virus that is being studied as a treatment for cancer. PV701 belongs to a family of viruses that cause Newcastle disease in birds.

pyrazine diazohydroxide
An anticancer drug.

pyrazoloacridine
An anticancer drug that belongs to the family of drugs called acridines.

pyroxamide
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called histone deacetylase inhibitors.

Q

Q10
A substance found in most tissues in the body, and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, CoQ10, vitamin Q10, and ubiquinone.

QS21
A plant extract that may improve the ability of the immune system to respond to disease. It is being studied in combination with vaccine therapy.

quadrantectomy
Surgical removal of the region of the breast (approximately one quarter) containing cancer.

quality of life
The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual's sense of well-being and ability to carry out various tasks.

R

R-flurbiprofen
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs).

r-tPA
Recombinant tissue plasminogen activator. A protein that is made by the body and that helps dissolve blood clots. It can also be made in the laboratory and is used in the treatment of heart attack and stroke. It is also being studied in the treatment of cancer. r-tPA belongs to the family of drugs called systemic thrombolytic agents. Also called tissue plasminogen activator (tPA), Activase, and Alteplase.

R101933
A substance that is being studied for its ability to make cancer cells respond to drugs to which they have become resistant. It belongs to the family of drugs called multidrug resistance inhibitors.

R115777
An anticancer drug that inhibits the transformation of normal cells to cancer cells. It belongs to the family of drugs called enzyme inhibitors. Also called tipifarnib.

rabies
A disease of the nervous system caused by the rabies virus. Rabies is marked by an increase in saliva production, abnormal behavior, and eventual paralysis and death.

radiation  (ray-dee-AY-shun)
Energy released in the form of particles or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, and medical x-rays.

radiation fibrosis  (ray-dee-AY-shun fye-BRO-sis)
The formation of scar tissue as a result of radiation therapy.

radiation nurse
A health professional who specializes in caring for people who are receiving radiation therapy.

radiation oncologist  (ray-dee-AY-shun on-KOL-o-jist)
A doctor who specializes in using radiation to treat cancer.

radiation physicist
A person who makes sure that the radiation machine delivers the right amount of radiation to the correct site in the body. The physicist works with the radiation oncologist to choose the treatment schedule and dose that has the best chance of killing the most cancer cells.

radiation surgery
A radiation therapy technique that delivers radiation directly to the tumor while sparing the healthy tissue. Also called radiosurgery and stereotactic external beam irradiation.

radiation therapist
A health professional who gives radiation treatment.

radiation therapy  (ray-dee-AY-shun THER-ah-pee)
The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Also called radiotherapy.

radical cystectomy  (RAD-ih-kal sis-TEK-toe-mee)
Surgery to remove the bladder as well as nearby tissues and organs.

radical hysterectomy
Surgery to remove the uterus, cervix, and part of the vagina. The ovaries, fallopian tubes, and nearby lymph nodes may also be removed.

radical lymph node dissection
A surgical procedure to remove most or all of the lymph nodes that drain lymph from the area around a tumor. The lymph nodes are then examined under a microscope to see if cancer cells have spread to them.

radical mastectomy  (RAD-ih-kul mas-TEK-toe-mee)
Surgery for breast cancer in which the breast, chest muscles, and all of the lymph nodes under the arm are removed. For many years, this was the breast cancer operation used most often, but it is used rarely now. Doctors consider radical mastectomy only when the tumor has spread to the chest muscles. Also called the Halsted radical mastectomy.

radical nephrectomy  (neh-FREK-tuh-mee)
Surgery to remove an entire kidney, nearby adrenal gland and lymph nodes, and other surrounding tissue.

radical perineal prostatectomy  (RAD-i-kul peh-ri-NEE-al pros-ta-TEK-toe-mee)
Surgery to remove all of the prostate through an incision between the scrotum and the anus. Nearby lymph nodes are sometimes removed through a separate incision in the wall of the abdomen.

radical prostatectomy  (RAD-ih-kal pros-ta-TEK-toe-mee)
Surgery to remove the entire prostate. The two types of radical prostatectomy are retropubic prostatectomy and perineal prostatectomy.

radical retropubic prostatectomy  (RAD-i-kul re-tro-PYOO-bik pros-ta-TEK-toe-mee)
Surgery to remove all of the prostate and nearby lymph nodes through an incision in the wall of the abdomen.

radioactive  (RAY-dee-o-AK-tiv)
Giving off radiation.

radioactive drug
A drug containing a radioactive substance that is used in the diagnosis and treatment of cancer and in pain management of bone metastases. Also called a radiopharmaceutical.

radioactive fallout  (RAY-dee-o-AK-tiv)
Airborne radioactive particles that fall to the ground during and after an atomic bombing, nuclear weapons test, or nuclear plant accident.

radioactive iodine  (RAY-dee-o-AK-tiv EYE-uh-dine)
A radioactive form of iodine, often used for imaging tests or as a treatment for thyroid cancer and certain other cancers. For imaging tests, the patient takes a small dose of radioactive iodine that collects in thyroid cells and certain kinds of tumors and can be detected by a scanner. For treatment of thyroid cancer, the patient takes a large dose of radioactive iodine, which kills thyroid cells. Radioactive iodine is also used in internal radiation therapy for prostate cancer, intraocular (eye) melanoma, and carcinoid tumors. The radioactive iodine is given by infusion or sealed in seeds, which are placed in or near the tumor to kill cancer cells.

radioactive palladium
A radioactive form of palladium (a metallic element that resembles platinum). When used to treat prostate cancer, radioactive seeds (small pellets that contain radioactive palladium) are placed in the prostate. Cancer cells are killed by the energy given off as the radioactive material decays (breaks down).

radioactive seed
A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material decays (breaks down).

radiofrequency ablation
The use of electrodes to heat and destroy abnormal tissue.

radioimmunoguided surgery
A procedure that uses radiolabeled substances to detect tumors for surgical removal.

radioimmunotherapy
Treatment with a radioactive substance that is linked to an antibody that will attach to the tumor when injected into the body.

radioisotope
An unstable element that releases radiation as it breaks down. Radioisotopes can be used in imaging tests or as a treatment for cancer.

radiolabeled
Any compound that has been joined with a radioactive substance.

radiologic exam
A test that uses radiation or other imaging procedures to find signs of cancer or other abnormalities.

radiologist  (RAY-dee-OL-o-jist)
A doctor who specializes in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, sound waves, or other types of energy.

radiology
The use of radiation (such as x-rays) or other imaging technologies (such as ultrasound and magnetic resonance imaging) to diagnose or treat disease.

radionuclide scanning
A test that produces pictures (scans) of internal parts of the body. The person is given an injection or swallows a small amount of radioactive material; a machine called a scanner then measures the radioactivity in certain organs.

radiopharmaceutical
A drug containing a radioactive substance that is used in the diagnosis and treatment of cancer and in pain management of bone metastases. Also called a radioactive drug.

radiosensitization
The use of a drug that makes tumor cells more sensitive to radiation therapy.

radiosensitizer
A drug that makes tumor cells more sensitive to radiation therapy.

radiosurgery
A radiation therapy technique that delivers radiation directly to the tumor while sparing the healthy tissue. Also called radiation surgery and stereotactic external beam irradiation.

radiotherapy  (RAY-dee-o-THER-a-pee)
The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiotherapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Also called radiation therapy.

radon  (RAY-don)
A radioactive gas that is released by uranium, a substance found in soil and rock. Breathing in too much radon can damage lung cells and lead to lung cancer.

raloxifene
A drug that belongs to the family of drugs called selective estrogen receptor modulators (SERMs) and is used in the prevention of osteoporosis in postmenopausal women. Raloxifene is also being studied as a cancer prevention drug.

raltitrexed
An anticancer drug that stops tumor cells from growing by blocking the ability of cells to make DNA. Also called ICI D1694. It belongs to the family of drugs called thymidylate synthase inhibitors.

randomization
When referring to an experiment or clinical trial, the process by which animal or human subjects are assigned by chance to separate groups that compare different treatments or other interventions. Randomization gives each participant an equal chance of being assigned to any of the groups.

randomized clinical trial
A study in which the participants are assigned by chance to separate groups that compare different treatments; neither the researchers nor the participants can choose which group. Using chance to assign people to groups means that the groups will be similar and that the treatments they receive can be compared objectively. At the time of the trial, it is not known which treatment is best. It is the patient's choice to be in a randomized trial.

ranpirnase
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called ribonuclease enzymes. Also called Onconase®.

rapamycin
A drug used to help prevent the body from rejecting organ and bone marrow transplants. It is also being studied as a treatment for cancer. Rapamycin belongs to the family of drugs called immunosuppressants. It is now called sirolimus.

rapid hormone cycling
A procedure in which drugs that block the production of male hormones are alternated with male hormones and/or drugs that promote the production of male hormones. This procedure is being studied in the treatment of prostate cancer.

rapid-onset opioid
An opioid that relieves pain quickly.

ras gene
A gene that has been found to cause cancer when it is altered (mutated). Agents that block its activity may stop the growth of cancer. A ras peptide is a protein fragment produced by the ras gene.

rasburicase
A laboratory-made form of the enzyme urate oxidase. Rasburicase is used to treat high levels of uric acid in children receiving treatment for cancer.

rattlesnake root
Cimicifuga racemosa. An eastern North American perennial herb. A substance obtained from the root of the plant has been used in some cultures to treat a number of medical problems. It is being studied in the treatment of hot flashes and other symptoms of menopause. The plant is also called black cohosh, black snakeroot, bugwort, and bugbane.

ravuconazole
A substance being studied in the treatment of infections caused by fungi. It belongs to the family of drugs called antifungal agents.

RBC
Red blood cell. RBCs carry oxygen to all parts of the body.

rebeccamycin
An anticancer drug that belongs to the family of drugs called antineoplastic antibiotics.

receptor
A molecule inside or on the surface of a cell that binds to a specific substance and causes a specific physiologic effect in the cell.

recombinant
Made through genetic engineering, which is also called gene splicing or recombinant DNA technology. By putting animal or plant genes into the genetic material of bacteria or yeast cells, these microorganisms can be turned into "factories" to make proteins for medical uses.

recombinant tissue plasminogen activator
r-tPA. A protein that is made by the body and that helps dissolve blood clots. It can also be made in the laboratory and is used in the treatment of heart attack and stroke. It is also being studied in the treatment of cancer. r-tPA belongs to the family of drugs called systemic thrombolytic agents. Also called tissue plasminogen activator (tPA), Activase, and Alteplase.

reconstructive surgeon
A doctor who can surgically reshape or rebuild (reconstruct) a part of the body, such as a woman's breast after surgery for breast cancer.

reconstructive surgery
Surgery that is done to reshape or rebuild (reconstruct) a part of the body changed by previous surgery.

rectal
By or having to do with the rectum. The rectum is the last several inches of the large intestine and ends at the anus.

rectum
The last several inches of the large intestine and ends at the anus.

recur
To occur again.

recurrence
The return of cancer, at the same site as the original (primary) tumor or in another location, after the tumor had disappeared.

recurrent cancer
Cancer that has returned after a period of time during which the cancer could not be detected. The cancer may come back to the same site as the original (primary) tumor or to another place in the body.

red blood cell
RBC. A cell that carries oxygen to all parts of the body. Also called an erythrocyte.

red clover
Trifolium pratense. A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover and wild clover.

red date
The fruit of the jujube plant. It has been used in some cultures to treat certain medical problems.

red elm
Ulmus fulva or Ulmus rubra. The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, gray elm, Indian elm, and sweet elm.

Reed-Sternberg cell
A type of cell that appears in people with Hodgkin's disease. The number of these cells increases as the disease advances.

reflux
The term used when liquid backs up into the esophagus from the stomach.

refractory
In medicine, describes a disease or condition that does not respond to treatment.

refractory cancer
Cancer that has not responded to treatment.

regimen
A treatment plan that specifies the dosage, the schedule, and the duration of treatment.

regional
In oncology, describes the body area right around a tumor.

regional cancer
Refers to cancer that has grown beyond the original (primary) tumor to nearby lymph nodes or organs and tissues.

regional chemotherapy  (kee-mo-THER-a-pee)
Treatment with anticancer drugs directed to a specific area of the body.

regional enteritis
Inflammation of the intestines, but usually only of the small intestine. Regional enteritis increases the risk for developing colon cancer. Also called Crohn's disease.

regional lymph node
In oncology, a lymph node that drains lymph from the region around a tumor.

regional lymph node dissection
A surgical procedure to remove some of the lymph nodes that drain lymph from the area around a tumor. The lymph nodes are then examined under a microscope to see if cancer cells have spread to them.

regression
A decrease in the size of a tumor or in the extent of cancer in the body.

rehabilitation specialist
A health care professional who helps people recover from an illness or injury and return to daily life. Examples of rehabilitation specialists are physical therapists and occupational therapists.

relapse
The return of signs and symptoms of cancer after a period of improvement.

relative survival rate
A specific measurement of survival. For cancer, the rate is calculated by adjusting the survival rate to remove all causes of death except cancer. The rate is determined at specific time intervals, such as 2 years and 5 years after diagnosis.

relaxation technique
A method used to reduce tension and anxiety, and control pain.

remission
A decrease in or disappearance of signs and symptoms of cancer. In partial remission, some, but not all, signs and symptoms of cancer have disappeared. In complete remission, all signs and symptoms of cancer have disappeared, although cancer still may be in the body.

remission induction therapy
The initial chemotherapy a person receives to bring about a remission.

remote brachytherapy
A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote brachytherapy or high-dose-rate remote radiation therapy.

renal artery
The main blood vessel that supplies blood to a kidney and its nearby adrenal gland and ureter. There is a renal artery for each kidney.

renal capsule
The fibrous connective tissue that surrounds each kidney.

renal cell cancer
The most common type of kidney cancer. It begins in the lining of the renal tubules in the kidney. The renal tubules filter the blood and produce urine. Also called hypernephroma.

renal collecting tubule
The last part of a long, twisting tube that collects urine from the nephrons (cellular structures in the kidney that filter blood and form urine) and moves it into the renal pelvis and ureters. Also called collecting duct.

renal fascia
A fibrous envelope of tissue that surrounds the kidney. Also called Gerota's fascia and Gerota's capsule.

renal glomerulus
A tiny, round cluster of blood vessels within the kidneys. It filters the blood to reabsorb useful materials and remove waste as urine.

renal pelvis
The area at the center of the kidney. Urine collects here and is funneled into the ureter, the tube that connects the kidney to the bladder.

renal tubular acidosis  (REE-nal TOO-bu-lar as-ih-DO-sis)
A rare disorder in which structures in the kidney that filter the blood are impaired, producing urine that is more acid than normal.

replicate
To make a copy or duplicate of something.

replication cycle
In biology, refers to the reproduction cycle of viruses. A repliction cycle begins with the infection of a host cell and ends with the release of mature progeny virus particles.

reproductive cell
An egg or sperm cell. Each mature reproductive cell carries a single set of 23 chromosomes.

reproductive system
In women, this system includes the ovaries, the fallopian tubes, the uterus (womb), the cervix, and the vagina (birth canal). The reproductive system in men includes the prostate, the testes, and the penis.

resectable  (ree-SEK-tuh-bull)
Part or all of an organ that can be removed with surgery.

resected
Surgical removal of part or all of an organ.

resection  (ree-SEK-shun)
Removal of tissue or part or all of an organ by surgery.

residual disease
Cancer cells that remain after attempts to remove the cancer have been made.

resistance
Failure of a cancer to shrink after treatment.

resorption
A process in which a substance, such as tissue, is lost by being destroyed and then absorbed by the body.

respiratory syncytial virus
RSV. A virus that causes respiratory infections with cold-like symptoms.

respiratory system  (RES-pih-ra-tor-ee)
The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. Also known as the respiratory tract.

respiratory therapy  (RES-pih-ra-tor-ee)
Exercises and treatments that help improve or restore lung function.

respiratory tract
The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. Also known as the respiratory system.

response
In medicine, an improvement related to treatment.

response rate
The percentage of patients whose cancer shrinks or disappears after treatment.

resting
In biology, refers to a cell that is not dividing.

retinoblastoma
An eye cancer that most often occurs in children younger than 5 years. It occurs in hereditary and nonhereditary (sporadic) forms.

retinoid
Vitamin A or a vitamin A-like compound.

retinol
Vitamin A. It is essential for proper vision and healthy skin and mucous membranes. Retinol is being studied for cancer prevention; it belongs to the family of drugs called retinoids.

retinyl palmitate
A drug being studied in cancer prevention. It belongs to the family of drugs called retinoids.

retroperitoneal  (RET-row-PAIR-ih-toe-NEE-ul)
Having to do with the area outside or behind the peritoneum (the tissue that lines the abdominal wall and covers most of the organs in the abdomen).

retropubic prostatectomy  (re-tro-PYOO-bik pros-ta-TEK-toe-mee)
Surgery to remove the prostate through an incision made in the abdominal wall.

retrospective
Looking back at events that have already taken place.

retrospective cohort study
A research study in which the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) are compared for a particular outcome (such as lung cancer). Also called a historic cohort study.

retrospective study
A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls). Researchers study the medical and lifestyle histories of the people in each group to learn what factors may be associated with the disease or condition. For example, one group may have been exposed to a particular substance that the other was not. Also called a case-control study.

retroviral vector
RNA from a virus that is used to insert genetic material into cells.

retrovirus
A type of virus that has RNA instead of DNA as its genetic material. It uses an enzyme called reverse transcriptase to become part of the host cells’ DNA. This allows many copies of the virus to be made in the host cells. The virus that causes AIDS, the human immunodeficiency virus (HIV), is a type of retrovirus.

RevM10 gene
An antiviral gene being studied for treatment of cancer in patients who have HIV, the virus that causes AIDS.

rhabdoid tumor
A malignant tumor of either the central nervous system (CNS) or the kidney. Malignant rhabdoid tumors of the CNS often have an abnormality of chromosome 22. These tumors usually occur in children younger than 2 years.

rhabdomyosarcoma
A malignant tumor of muscle tissue.

rheumatism
A group of disorders marked by inflammation or pain in the connective tissue structures of the body. These structures include bone, cartilage, and fat.

rhinoscope
A thin lighted tube used to examine the nose. Also called a nasoscope.

rhinoscopy
A procedure in which a thin, lighted tube is inserted into the nose to look for abnormal areas. Also called nasoscopy.

rhizoxin
An anticancer drug isolated from a fungus. It is similar to the family of drugs called vinca alkaloids.

rhubarb
Rheum palmatum or Rheum officinale. The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Also called da-huang, Chinese rhubarb, Indian rhubarb, and Turkish rhubarb.

ribavirin
A drug used to treat respiratory syncytial virus (RSV) infection in the lungs.

ribonucleic acid
RNA. One of the two types of nucleic acids found in all cells. The other is deoxyribonucleic acid (DNA). Ribonucleic acid transmits genetic information from DNA to proteins produced by the cell.

ribonucleotide reductase inhibitor
A family of anticancer drugs that interfere with the growth of tumor cells by blocking the formation of deoxyribonucleotides (building blocks of DNA).

rifampin
A drug that is used to treat infections caused by bacteria. It belongs to the family of drugs called antibiotics.

risedronate  (ris-ED-roe-nate)
A substance that is being studied in the prevention and treatment of osteoporosis. It belongs to the family of drugs called bone resorption inhibitors.

risk factor
Something that may increase the chance of developing a disease. Some examples of risk factors for cancer include age, a family history of certain cancers, use of tobacco products, certain eating habits, obesity, exposure to radiation or other cancer-causing agents, and certain genetic changes.

ritonavir
A drug that belongs to the family of drugs called protease inhibitors. It interferes with the ability of a virus to make copies of itself.

rituximab
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

RK-0202
A substance that is being studied in the prevention of oral mucositis in patients receiving radiation therapy or chemotherapy for head and neck cancer.

RMP-7
A substance that is being studied for its ability to help other drugs reach the brain. It belongs to the family of drugs called bradykinin agonists. Also called lobradimil.

RNA
Ribonucleic acid. One of the two types of nucleic acids found in all cells. The other is deoxyribonucleic acid (DNA). RNA transmits genetic information from DNA to proteins produced by the cell.

Ro 31-7453
An anticancer drug that may prevent cancer cells from dividing.

Ro 50-3821
A substance that is being studied in the treatment of anemia in patients who are receiving chemotherapy. It is a form of erythropoietin (a substance produced in the kidneys that stimulates the production of red blood cells) that has been changed in the laboratory. Also called methoxypolyethylene glycol epoetin beta.

rofecoxib
A substance used for pain relief that is also being studied for its ability to prevent cancer and to block the growth of new blood vessels to solid tumors. It belongs to the family of drugs called nonsteroidal anti-inflammatory drugs.

rosiglitazone
A drug taken to help reduce the amount of sugar in the blood. Rosiglitazone helps make insulin more effective and improves regulation of blood sugar. It belongs to the family of drugs called thiazolidinediones.

RPI.4610
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called angiogenesis inhibitors.

RPR 109881A
A drug that belongs to the family of anticancer drugs called taxanes.

RSR13
A drug that may increase the effectiveness of radiation therapy. Also called efaproxiral.

RSV
Respiratory syncytial virus. A virus that causes respiratory infections with cold-like symptoms.

S

S-1
A drug that is being studied for its ability to enhance the effectiveness of fluorouracil and prevent gastrointestinal side effects caused by fluorouracil. It belongs to the family of drugs called antimetabolites.

S-phase fraction
A measure of the percentage of cells in a tumor that are in the phase of the cell cycle during which DNA is synthesized. The S-phase fraction may be used with the proliferative index to give a more complete understanding of how fast a tumor is growing.

saline
A solution of salt and water.

saliva  (suh-LIE-vuh)
The watery fluid made by mucous glands in the mouth. It moistens food to aid in digestion.

salivary gland  (SAL-ih-vair-ee)
A gland in the mouth that produces saliva.

salpingo-oophorectomy  (sal-PIN-go o-o-for-EK-toe-mee)
Surgical removal of the fallopian tubes and ovaries.

salvage therapy
Treatment that is given after the cancer has not responded to other treatments.

samarium 153
A radioactive substance used in cancer therapy.

saponin
A substance found in soybeans and many other plants. Saponins may help lower cholesterol and may have anticancer effects.

saquinavir mesylate
A drug that belongs to the family of drugs called protease inhibitors. It interferes with the ability of a virus to make copies of itself.

sarCNU
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called alkylating agents. Also called sarcosinamide nitrosourea.

sarcoid
An inflammatory disease marked by the formation of granulomas (small nodules of immune cells) in the lungs, lymph nodes, and other organs. Sarcoid may be acute and go away by itself, or it may be chronic and progressive. Also called sarcoidosis.

sarcoidosis
An inflammatory disease marked by the formation of granulomas (small nodules of immune cells) in the lungs, lymph nodes, and other organs. Sarcoidosis may be acute and go away by itself, or it may be chronic and progressive. Also called sarcoid.

sarcoma
A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

sarcosinamide nitrosourea
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called alkylating agents. Also called sarCNU.

sargramostim
A colony-stimulating factor that stimulates the production of white blood cells, especially granulocytes and macrophages, and cells (in the bone marrow) that are precursors of platelets. It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called granulocyte-macrophage colony-stimulating factor (GM-CSF).

satraplatin
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called platinum analogs. Also called BMS-182751 and JM 216.

SC-70935
A substance that is being studied for its ability to stimulate the production of blood cells during chemotherapy. It belongs to the family of drugs called colony-stimulating factors. Also known as leridistim.

scalpel  (SKAL-pul)
A small, thin knife used for surgery.

scan
A picture of structures inside the body. Scans often used in diagnosing, staging, and monitoring disease include liver scans, bone scans, and computed tomography (CT) or computerized axial tomography (CAT) scans and magnetic resonance imaging (MRI) scans. In liver scanning and bone scanning, radioactive substances that are injected into the bloodstream collect in these organs. A scanner that detects the radiation is used to create pictures. In CT scanning, an x-ray machine linked to a computer is used to produce detailed pictures of organs inside the body. MRI scans use a large magnet connected to a computer to create pictures of areas inside the body.

SCH 54031
An anticancer drug that belongs to the family of drugs called biological response modifiers. SCH 54031 is a cytokine. Also called PEG-interferon alfa-2b.

SCH 66336
An anticancer drug that belongs to the family of drugs called enzyme inhibitors. Also called lonafarnib.

SCH-58500
A drug that inhibits the growth of tumor cells that express the mutated p53 gene.

schedule
In clinical trials, the step-by-step plan for how patients are to be treated; for example, which drugs are to be given, the order and method by which they are to be given, the length of time of each infusion, the amount of time between courses, and the total length of treatment.

Schiller test  (SHIL-er)
A test in which iodine is applied to the cervix. The iodine colors healthy cells brown; abnormal cells remain unstained, usually appearing white or yellow.

Schwann cell
A type of glial cell of the peripheral nervous system that helps separate and insulate nerve cells.

schwannoma  (shwah-NO-ma)
A tumor of the peripheral nervous system that arises in the nerve sheath (protective covering). It is almost always benign, but rare malignant schwannomas have been reported.

scientist
A person who has studied science, especially one who is active in a particular field of investigation.

scleroderma
A chronic disorder marked by hardening and thickening of the skin. Scleroderma can be localized or it can affect the entire body (systemic).

screening
Checking for disease when there are no symptoms.

screening mammogram
X-rays of the breasts taken to check for breast cancer in the absence of signs or symptoms.

scrotum  (SKRO-tum)
In males, the external sac that contains the testicles.

Scutellaria barbata
An herb that belongs to a group of herbs named the Scutellaria species or scullcap. Both the root and the above-ground part have been used to make herbal medicines. The root has been used in traditional Chinese medicine to treat lung cancer and other medical problems.

SDX-102
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called antimetabolites. Also called alanosine.

sebum  (SEE-bum)
An oily substance produced by certain glands in the skin.

second cancer
Refers to a new primary cancer that is caused by previous cancer treatment, or a new primary cancer in a person with a history of cancer.

second-line therapy
Treatment that is given when initial treatment (first-line therapy) doesn’t work, or stops working.

second-look surgery
Surgery performed after primary treatment to determine whether tumor cells remain.

secondary cancer
Cancer that has spread from the organ in which it first appeared to another organ. For example, breast cancer cells may spread (metastasize) to the lungs and cause the growth of a new tumor. When this happens, the disease is called metastatic breast cancer, and the tumor in the lungs is called a secondary tumor. Also called secondary tumor.

secondary tumor
Cancer that has spread from the organ in which it first appeared to another organ. For example, breast cancer cells may spread (metastasize) to the lungs and cause the growth of a new tumor. When this happens, the disease is called metastatic breast cancer and the tumor in the lungs is called a secondary tumor. Also called secondary cancer.

sedimentation rate
The distance red blood cells travel in one hour in a sample of blood as they settle to the bottom of a test tube. The sedimentation rate is increased in inflammation, infection, cancer, rheumatic diseases, and diseases of the blood and bone marrow. Also called erythrocyte sedimentation rate.

sedoxantrone trihydrochloride
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called DNA-intercalating compounds. Also called CI-958.

segmental cystectomy  (sis-TEK-to-mee)
The removal of cancer as well as some of the bladder tissue around the tumor. Sometimes called partial cystectomy.

segmental mastectomy  (mas-TEK-toe-mee)
The removal of cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are also taken out. Also called partial mastectomy.

seizure  (SEE-zhur)
Convulsion; a sudden, involuntary movement of the muscles.

selection bias
An error in choosing the individuals or groups to take part in a study. Ideally, the subjects in a study should be very similar to one another and to the larger population from which they are drawn (for example, all individuals with the same disease or condition). If there are important differences, the results of the study may not be valid.

selective estrogen receptor modulator  (sel-EK-tiv ESS-tro-jen re-SEP-tor MOD-yew-lay-tor)
SERM. A drug that acts like estrogen on some tissues but blocks the effect of estrogen on other tissues. Tamoxifen and raloxifene are SERMs.

selective serotonin reuptake inhibitor
SSRI. A type of drug that is used to treat depression. SSRIs slow the process by which serotonin (a substance that nerves use to send messages to one another) is reused by nerve cells that make it. This increases the amount of serotonin available for stimulating other nerves.

selenium
An essential dietary mineral.

sella turcica
A depression of the bone at the base of the skull where the pituitary gland is located.

semaxanib
An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Also called SU5416.

semen
The fluid that is released through the penis during orgasm. Semen is made up of sperm from the testicles and fluid from the prostate and other sex glands.

seminal fluid  (SEM-in-al)
Fluid from the prostate and other sex glands that helps transport sperm out of the man's body during orgasm. Seminal fluid contains sugar as an energy source for sperm.

seminal vesicle  (SEM-in-al VES-ih-kul)
A gland that helps produce semen.

seminal vesicle biopsy
The removal of fluid or tissue with a needle from the seminal vesicles for examination under a microscope. The seminal vesicles are glands in the male reproductive tract that produce a part of semen.

seminoma  (sem-in-O-ma)
A type of cancer of the testicles. Seminomas may spread to the lung, bone, liver, or brain.

semustine
An anticancer drug that belongs to the family of drugs called alkylating agents.

senega root
The root of an herb called Polygala senega. It has been used in some cultures to treat certain medical problems, including problems of the respiratory system.

senile keratosis
A precancerous condition of thick, scaly patches of skin. Also called solar or actinic keratosis.

sensitivity
When referring to a medical test, sensitivity refers to the percentage of people who test positive for a specific disease among a group of people who have the disease. No test has 100% sensitivity because some people who have the disease will test negative for it (false negatives).

sensor
A device that responds to a stimulus, such as heat, light, or pressure, and generates a signal that can be measured or interpreted.

sensory
Having to do with the senses.

sentinel lymph node
The first lymph node to which cancer is likely to spread from the primary tumor. Cancer cells may appear first in the sentinel node before spreading to other lymph nodes.

sentinel lymph node biopsy
Removal and examination of the sentinel node(s) (the first lymph node(s) to which cancer cells are likely to spread from a primary tumor). To identify the sentinel lymph node(s), the surgeon injects a radioactive substance, blue dye, or both near the tumor. The surgeon then uses a scanner to find the sentinel lymph node(s) containing the radioactive substance or looks for the lymph node(s) stained with dye. The surgeon then removes the sentinel node(s) to check for the presence of cancer cells.

sentinel lymph node mapping
The use of dyes and radioactive substances to identify the first lymph node to which cancer is likely to spread from the primary tumor. Cancer cells may appear first in the sentinel node before spreading to other lymph nodes and other places in the body.

seocalcitol
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called vitamin D analogs.

sepsis  (SEP-sis)
The presence of bacteria or their toxins in the blood or tissues.

septate  (SEP-tate)
An organ or structure that is divided into compartments.

septicemia
Disease caused by the spread of bacteria and their toxins in the bloodstream. Also called blood poisoning.

sequential treatment
One treatment after the other.

SERM
Selective estrogen receptor modulator. A drug that acts like estrogen on some tissues but blocks the effect of estrogen on other tissues. Tamoxifen and raloxifene are SERMs.

serotonin
A hormone found in the brain, platelets, digestive tract, and pineal gland. It acts both as a neurotransmitter (a substance that nerves use to send messages to one another) and a vasoconstrictor (a substance that causes blood vessels to narrow). A lack of serotonin in the brain is thought to be a cause of depression. Also called 5-hydroxytryptamine.

serous  (SEER-us)
Having to do with serum, the clear liquid part of blood.

sertraline
A drug that is used to treat depression. It belongs to the family of drugs called selective serotonin reuptake inhibitors (SSRIs). Also called Zoloft®.

serum
The clear liquid part of the blood that remains after blood cells and clotting proteins have been removed.

serum albumin
The main protein in blood plasma. Low levels of serum albumin occur in people with malnutrition, inflammation, and serious liver and kidney disease.

serum glutamate pyruvate transaminase
SGPT. An enzyme found in the liver and other tissues. A high level of serum glutamate pyruvate transaminase released into the blood may be a sign of liver damage, cancer, or other diseases. Also called alanine transferase.

serum glutamic-oxaloacetic transaminase
SGOT. An enzyme found in the liver, heart, and other tissues. A high level of serum glutamic-oxaloacetic transaminase released into the blood may be a sign of liver or heart damage, cancer, or other diseases. Also called aspartate transaminase.

serum tumor marker test
A blood test that measures the amount of substances called tumor markers (or biomarkers). Tumor markers are released into the blood by tumor cells or by other cells in response to tumor cells. A high level of a tumor marker may be a sign of cancer.

sesquiterpene lactone
A substance found in some plants. Sesquiterpene lactones may have anti-inflammatory and anticancer effects. Plants containing sesquiterpene lactones have been used in some cultures to treat certain medical problems.

severe myelosuppression
Severe reduction in the numbers of red blood cells, white blood cells, and platelets in the bone marrow. Severe myelosuppression is a side effect of some cancer treatments. Also called myeloablation.

Sézary syndrome
A form of cutaneous T-cell lymphoma, a cancerous disease that affects the skin.

SGN-00101
A substance that is being studied in the prevention of cancer. It belongs to the family of drugs called fusion proteins.

SGN-15
A substance that combines a monoclonal antibody with the chemotherapy drug doxorubicin. The monoclonal antibody helps deliver doxorubicin directly to tumor cells. SGN-15 belongs to the family of drugs called antibody drug conjugates. Also called cBR96-doxorubicin immunoconjugate.

SGOT
Serum glutamic-oxaloacetic transaminase. An enzyme found in the liver, heart, and other tissues. A high level of SGOT released into the blood may be a sign of liver or heart damage, cancer, or other diseases. Also called aspartate transaminase.

SGPT
Serum glutamate pyruvate transaminase. An enzyme found in the liver and other tissues. A high level of SGPT released into the blood may be a sign of liver damage, cancer, or other diseases. Also called alanine transferase.

sham therapy
An inactive treatment or procedure that is intended to mimic as closely as possible a therapy in a clinical trial. Also called placebo therapy.

shave biopsy  (BY-ahp-see)
A procedure in which a skin abnormality and a thin layer of surrounding skin are removed with a small blade for examination under a microscope. Stitches are not needed with this procedure.

sheep sorrel
Rumex acetosella. A plant that has been used in some cultures to treat certain medical problems. It may have anticancer effects. Also called dock and sorrel.

shiitake mushroom
Lentinus edodes. A dark oriental mushroom widely used as a food. Several anticancer substances have been found in shiitake mushrooms, including lentinan, which has been studied in Japan as a treatment for stomach and colorectal cancer.

Sho-saiko-to
A Japanese formulation of seven Chinese herbs that is being studied as a treatment for cancer.

shunt
A surgeon implants or creates a shunt to move blood or other fluid from one part of the body to another part. For example, a surgeon may implant a tube to drain cerebrospinal fluid from the brain to the abdomen. A surgeon may also change normal blood flow by joining two blood vessels together.

sialic acid
A type of sugar molecule.

sialyl Tn-KLH
A vaccine composed of a substance that enhances immunity plus an antigen found on some tumors of the colon, breast, lung, ovary, pancreas, and stomach.

side effect
A problem that occurs when treatment affects tissues or organs other than the ones being treated. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

side-to-end coloanal anastomosis
A surgical procedure in which the side of the colon is attached to the anus after the rectum has been removed. A section of the colon about 2 inches long is formed into a mini-pouch in order to replace the function of the rectum and store stool until it can be eliminated. This procedure is similar to the J-pouch coloanal anastomosis but a much smaller pouch is formed.

sigmoid colon  (SIG-moyd KO-lun)
The S-shaped section of the colon that connects to the rectum.

sigmoidoscope  (sig-MOY-da-skope)
A thin, lighted tube used to view the inside of the colon.

sigmoidoscopy  (sig-moid-OSS-ko-pee)
Inspection of the lower colon using a thin, lighted tube called a sigmoidoscope. Samples of tissue or cells may be collected for examination under a microscope. Also called proctosigmoidoscopy.

signal transduction inhibitor
A drug that may prevent the ability of cancer cells to multiply quickly and invade other tissues.

signet ring cell carcinoma
A highly malignant type of cancer typically found in glandular cells that line the digestive organs. The cells resemble signet rings when examined under a microscope.

SIL
Squamous intraepithelial lesion. A general term for the abnormal growth of squamous cells on the surface of the cervix. The changes in the cells are described as low grade or high grade, depending on how much of the cervix is affected and how abnormal the cells appear.

sildenafil
A substance that is used to treat erectile dysfunction. Sildenafil relaxes the smooth muscle of the penis to allow increased blood flow and erection. It belongs to the family of drugs called phosphodiesterase inhibitors. Also called Viagra.

silicone
A synthetic gel that is used as an outer coating on breast implants and as the inside filling of some implants.

Silybum marianum
A plant that has been used in some cultures to treat certain medical problems, including stomach, liver, and gallbladder disorders. The active extract of Silybum marianum seeds is called silymarin. It is being studied in the prevention of liver damage caused by some cancer treatments. Also called milk thistle.

silymarin
A substance obtained from milk thistle seeds that is being studied in the prevention of liver damage caused by certain cancer treatments.

simple mastectomy
Removal of the breast. Also called total mastectomy.

simple nephrectomy  (neh-FREK-tuh-mee)
Surgery to remove one kidney.

simulation
In cancer treatment, a process used to plan radiation therapy so that the target area is precisely located and marked.

single blind study
A type of clinical trial in which only the doctor knows whether a patient is taking the standard treatment or the new treatment being tested. This helps prevent bias in treatment studies.

single-photon emission computed tomography
SPECT. A special type of computed tomography (CT) scan in which a small amount of a radioactive drug is injected into a vein and a scanner is used to make detailed images of areas inside the body where the radioactive material is taken up by the cells. SPECT can give information about blood flow to tissues and chemical reactions (metabolism) in the body.

siplizumab
A monoclonal antibody that is being studied in the treatment of certain lymphoproliferative disorders and psoriasis. Also called MEDI-507.

sirolimus
A drug used to help prevent the body from rejecting organ and bone marrow transplants. It is also being studied as a treatment for cancer. Sirolimus belongs to the family of drugs called immunosuppressants. It was previously called rapamycin.

skeletal
Having to do with the skeleton (boney part of the body).

skeleton
The framework that supports the soft tissues of vertebrate animals and protects many of their internal organs. The skeletons of vertebrates are made of bone and/or cartilage.

skin graft
Skin that is moved from one part of the body to another.

skin patch
A bandage-like patch that releases medicine into the body through the skin. The medicine enters the blood slowly and steadily.

skin stimulation
The process of applying pressure, friction, temperature change, or chemical substances to the skin to lessen or block a feeling of pain.

skin test
A test for an immune response to a compound by placing it on or under the skin.

slippery elm
Ulmus fulva or Ulmus rubra. The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, and sweet elm.

small cell lung cancer
A type of lung cancer in which the cells appear small and round when viewed under the microscope. Also called oat cell lung cancer.

small intestine
The part of the digestive tract that is located between the stomach and the large intestine.

smoldering leukemia
Disease in which the bone marrow does not function normally. Also called preleukemia or myelodysplastic syndrome.

SMT-487
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called somatostatin analogs.

SnET2
An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents. Also called tin ethyl etiopurpurin.

SNX 111
A drug used in the treatment of chronic pain. Also called ziconotide.

soblidotin
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called tubulin inhibitors. Also called TZT-1027.

social worker
A professional trained to talk with people and their families about emotional or physical needs, and to find them support services.

sodium
A mineral needed by the body to keep body fluids in balance. Sodium is found in table salt and in many processed foods. Too much sodium can cause the body to retain water.

sodium borocaptate
BSH. A substance used in a type of radiation therapy called boron neutron capture therapy. BSH is injected into a vein, and becomes concentrated in tumor cells. The patient then receives radiation treatment with atomic particles called neutrons. The neutrons react with the boron in BSH, producing radioactive particles that kill the tumor cells without harming normal cells.

sodium salicylate
A drug that belongs to the family of drugs called nonsteroidal anti-inflammatory drugs. Sodium salicylate may be tolerated by people who are sensitive to aspirin.

sodium sulfite
A chemical used in photography, paper making, water treatment, and for other purposes.

sodium thiosulfate  (SO-dee-um thye-oh-SUL-fate)
A substance that is used in medicine as an antidote to cyanide poisoning and to decrease side effects of the anticancer drug cisplatin.

soft diet
A diet consisting of bland foods that are softened by cooking, mashing, pureeing, or blending.

soft tissue
Refers to muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

soft tissue sarcoma  (TISH-oo sar-KO-ma)
A sarcoma that begins in the muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

solar keratosis
A precancerous condition of thick, scaly patches of skin. Also called actinic or senile keratosis.

solid tumor
An abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancerous), or malignant (cancerous). Different types of solid tumors are named for the type of cells that form them. Examples of solid tumors are sarcomas, carcinomas, and lymphomas. Leukemias (cancers of the blood) generally do not form solid tumors.

somatic cell
Any of the body cells except the reproductive (germ) cells.

somatic mutation
An alteration in DNA that occurs after conception. Somatic mutations can occur in any of the cells of the body except the germ cells (sperm and egg) and therefore are not passed on to children. These alterations can (but do not always) cause cancer or other diseases.

somnolence syndrome  (SOM-no-lens)
Periods of drowsiness, lethargy, loss of appetite, and irritability in children following radiation therapy treatments to the head.

sonogram  (SON-o-gram)
A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called an ultrasonogram.

sorivudine
An antiviral drug that is being studied as a treatment for herpesvirus. It belongs to the family of drugs called nucleic acid synthesis inhibitors.

sorrel
Rumex acetosella. A plant that has been used in some cultures to treat certain medical problems. It may have anticancer effects. Also called sheep sorrel and dock.

specific immune cell
An immune cell such as a T or B lymphocyte that responds to a single, specific antigen.

specificity
When referring to a medical test, specificity refers to the percentage of people who test negative for a specific disease among a group of people who do not have the disease. No test is 100% specific because some people who do not have the disease will test positive for it (false positive).

SPECT
Single-photon emission computed tomography. A special type of computed tomography (CT) scan in which a small amount of a radioactive drug is injected into a vein and a scanner is used to make detailed images of areas inside the body where the radioactive material is taken up by the cells. SPECT can give information about blood flow to tissues and chemical reactions (metabolism) in the body.

speculum  (SPEK-yoo-lum)
An instrument used to widen an opening of the body to make it easier to look inside.

speech pathologist  (pa-THOL-o-jist)
A specialist who evaluates and treats people with communication and swallowing problems. Also called a speech therapist.

speech therapist
A specialist who evaluates and treats people with communication and swallowing problems. Also called a speech pathologist.

sperm
The male reproductive cell, formed in the testicle. A sperm unites with an egg to form an embryo.

sperm banking
Freezing sperm for use in the future. This procedure can allow men to father children after loss of fertility.

sperm retrieval
The doctor removes sperm from a man's testis or epididymis using a fine needle or another instrument.

SPF
Sun protection factor. A scale for rating the level of sunburn protection in sunscreen products. The higher the SPF, the more sunburn protection it provides. Sunscreens with an SPF value of 2 through 11 provide minimal protection against sunburns. Sunscreens with an SPF of 12 through 29 provide moderate protection, which is adequate for most people. Those with an SPF of 30 or higher provide high protection against sunburn and are sometimes recommended for people who are highly sensitive to the sun.

sphincter
A ring-shaped muscle that relaxes or tightens to open or close a passage or opening in the body. Examples are the anal sphincter (around the opening of the anus) and the pyloric sphincter (at the lower opening of the stomach).

spiculated mass  (SPIK-you-lay-ted...)
A lump of tissue with spikes or points on the surface.

spinal cord
A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.

spinal tap
A procedure in which a needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called a lumbar puncture.

spindle cell cancer
Cancer that arises in cells that appear spindle-shaped when viewed under a microscope. These cancers can occur in various places in the body, including the skin, lungs, kidney, breast, gastrointestinal tract, bone, and muscle.

spindle cell sarcoma
A type of connective tissue cancer in which the cells are spindle-shaped when examined under a microscope.

spiral CT scan
A detailed picture of areas inside the body. The pictures are created by a computer linked to an x-ray machine that scans the body in a spiral path. Also called helical computed tomography.

spleen
An organ that is part of the lymphatic system. The spleen produces lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen near the stomach.

splenectomy  (splen-EK-toe-mee)
An operation to remove the spleen.

splenomegaly
Enlarged spleen.

spotted thistle
Cnicus benedictus. A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Spotted thistle may have anti-inflammatory and anticancer effects. Also called blessed thistle, St. Benedict's thistle, cardin, and holy thistle.

sputum  (SPYOO-tum)
Mucus and other matter that is brought up from the lungs by coughing.

sputum cytology
Examination under a microscope of lung cells found in sputum (mucus and other matter brought up from the lungs by coughing) to check for cancer.

squalamine lactate
A drug that belongs to the family of drugs called angiogenesis inhibitors. It prevents the growth of new blood vessels into a solid tumor.

squamous cell  (SKWAY-mus)
A flat cell that looks like a fish scale under a microscope. Squamous cells cover internal and external surfaces of the body.

squamous cell carcinoma  (SKWAY-mus sel kar-sin-O-ma)
Cancer that begins in squamous cells, which are thin, flat cells that look like fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the passages of the respiratory and digestive tracts. Also called epidermoid carcinoma.

squamous intraepithelial lesion  (SKWAY-mus in-tra-eh-pih-THEEL-ee-ul LEE-zhun)
SIL. A general term for the abnormal growth of squamous cells on the surface of the cervix. The changes in the cells are described as low grade or high grade, depending on how much of the cervix is affected and how abnormal the cells appear.

SR-29142
A drug that may protect healthy tissue from the toxic effects of anticancer drugs.

SR-45023A
An anticancer drug that belongs to the family of drugs called bisphosphonates. It affects cancer cell receptors governing cell growth and cell death.

SR49059
An anticancer drug that inhibits a hormone growth factor responsible for stimulating some cancer cells to multiply.

SSRI
Selective serotonin reuptake inhibitor. A type of drug that is used to treat depression. SSRIs slow the process by which serotonin (a substance that nerves use to send messages to one another) is reused by nerve cells that make it. This increases the amount of serotonin available for stimulating other nerves.

St. Benedict's thistle
Cnicus benedictus. A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. St. Benedict's thistle may have anti-inflammatory and anticancer effects. Also called blessed thistle, cardin, holy thistle, and spotted thistle.

St. John's wort
Hypericum perforatum, an herbal product sold as an over-the-counter treatment for depression. It is being studied for its ability to lessen certain side effects of cancer treatment.

stable disease
Cancer that is neither decreasing nor increasing in extent or severity.

stage
The extent of a cancer within the body. If the cancer has spread, the stage describes how far it has spread from the original site to other parts of the body.

stage 0 bladder cancer
Cancer is found on tissue lining the inside of the bladder only. Stage 0 is divided into stage 0a and stage 0is, depending on the type of the tumor. Stage 0a is also called papillary carcinoma, which may look like tiny mushrooms growing from the lining of the bladder. Stage 0is is also called carcinoma in situ, which is a flat tumor on the tissue lining the inside of the bladder.

stage 0 cervical cancer
Cancer is found in the first layer of cells lining the cervix only and has not invaded the deeper tissues of the cervix. Also called carcinoma in situ.

stage 0 chronic lymphocytic leukemia
There are too many lymphocytes in the blood, but there are no other symptoms of leukemia. Stage 0 is indolent (slow-growing).

stage 0 colorectal cancer
Cancer is found in the innermost lining of the colon and/or rectum only. Also called carcinoma in situ.

stage 0 esophageal cancer
Cancer is found in the innermost layer of cells lining the esophagus. Also called carcinoma in situ.

stage 0 gastric cancer
Cancer is found in the inside lining of the mucosal (innermost) layer of the stomach wall. Also called carcinoma in situ.

stage 0 melanoma
Cancer is found in the epidermis (outer layer of the skin) only. Also called melanoma in situ.

stage 0 nasopharyngeal cancer
Cancer is found in the lining of the nasopharynx (the upper part of the throat behind the nose) only. Also called carcinoma in situ.

stage 0 non-small cell lung cancer
Cancer is limited to the lung. It is found in a few layers of cells only, and has not grown through the top lining of the lung. Also called carcinoma in situ.

stage 0 skin cancer
Cancer is found in the epidermis (topmost layer of the skin) only, in the layer of cells in which the cancer began. Also called carcinoma in situ.

stage 0 testicular cancer
Abnormal cells are found only in the tiny tubules where the sperm cells begin to develop. The cells do not invade normal tissues; all tumor marker levels are normal. Sometimes called a precancerous condition. Also called carcinoma in situ.

stage I adrenocortical cancer
Cancer that is smaller than 5 centimeters (smaller than 2 inches) and has not spread into tissues around the adrenal gland.

stage I adult Hodgkin's lymphoma
Stage I is divided into stage I and stage IE. In stage I, cancer is found in a single group of lymph nodes. In stage IE, cancer is found in one area or organ other than the lymph nodes.

stage I adult non-Hodgkin's lymphoma
Stage I is divided into stage I and stage IE. In stage I, cancer is found in a single lymph node area. In stage IE, cancer is found in an organ or tissue other than the lymph nodes.

stage I adult primary liver cancer
One tumor is present, which is no larger than 2 centimeters.

stage I anal cancer
Cancer that has spread beyond the top layer of anal tissue and is smaller than 2 centimeters (smaller than 1 inch).

stage I bladder cancer
Cancer has spread to the connective tissue layer below the inner lining of the bladder.

stage I breast cancer
The tumor is no larger than 2 centimeters and has not spread outside the breast.

stage I cancer of the uterus
Cancer found in only the main part of the uterus, not the cervix.

stage I cancer of the vulva
Cancer found in the vulva only or the space between the opening of the rectum and the vagina (perineum). The tumor is 2 centimeters (about 1 inch) or smaller.

stage I cervical cancer
Cancer is found in the cervix only. Stage I is divided into stages IA and IB, based on the amount of cancer that is found. In stage IA, a very small amount of cancer that can only be seen with a microscope is found in the tissues of the cervix. The cancer is not deeper than 5 millimeters and not wider than 7 millimeters. In stage IB, the cancer is still within the cervix and either (1) can only be seen with a microscope and is deeper than 5 millimeters or wider than 7 millimeters; or (2) can be seen without a microscope and may be larger than 4 centimeters.

stage I childhood non-Hodgkin's lymphoma
Cancer is found in a single area or lymph node outside of the abdomen or chest.

stage I chronic lymphocytic leukemia
There are too many lymphocytes in the blood and the lymph nodes are larger than normal.

stage I colorectal cancer
Cancer has spread beyond the innermost lining of the colon and/or rectum to the second and third layers and involves the inside wall of the colon and/or rectum, but it has not spread to the outer wall or outside the colon and/or rectum. Also called Dukes' A colorectal cancer.

stage I cutaneous T-cell lymphoma
May be either of the following: (1) stage IA cancer affecting less than 10% of the skin's surface and appearing as red, dry, scaly patches; (2) stage IB cancer affecting 10% or more of the skin's surface and appearing as red, dry, scaly patches.

stage I endometrial cancer
Cancer is found in the uterus only. Stage I is divided into stages IA, IB, and IC, based on how far the disease has spread from the endometrium into the muscles of the uterus.

stage I esophageal cancer
Cancer has spread beyond the innermost layer of cells to the next layer of tissue in the wall of the esophagus.

stage I gastric cancer
Stage I is divided into stage IA and stage IB, depending on where the cancer has spread. In stage IA, cancer has spread completely through the mucosal (innermost) layer of the stomach wall. In stage IB, cancer has spread completely through the mucosal (innermost) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor, or has spread to the muscularis (middle) layer of the stomach wall.

stage I hypopharynx cancer
Tumor that is confined to one area of the hypopharynx and is no larger than 2 centimeters (about 0.75 inch).

stage I kidney cancer
A tumor that is 7 centimeters (2.75 inches) or smaller.

stage I laryngeal cancer
Cancer that is only in the area where it started and has not spread to nearby lymph nodes or other parts of the body. The exact definition of stage I depends on whether the cancer started in the supraglottis (cancer in only one area of the supraglottis, and the vocal cords can move normally); the glottis (cancer in only the vocal cords, and the vocal cords can move normally); or the subglottis (cancer that has not spread outside the subglottis).

stage I lip and oral cavity cancer
Cancer that is no larger than 2 centimeters (about 1 inch) and has not spread to nearby lymph nodes.

stage I melanoma
Stage I is divided into stages IA and IB. In stage IA, the tumor is not more than 1 millimeter thick, with no ulceration. The tumor is in the epidermis (outer layer of skin) and upper layer of the dermis (inner layer of skin). In stage IB, the tumor is either not more than 1 millimeter thick, with ulceration, and may have spread into the dermis or the tissue below the skin; or 1 to 2 millimeters thick, with no ulceration.

stage I mesothelioma
Cancer found in the lining of the chest cavity near the lung and heart, in the diaphragm (the thin muscle below the lungs and heart that separates the chest from the abdomen), or in the lung.

stage I multiple myeloma
Relatively few cancer cells have spread throughout the body. There may be no symptoms of disease.

stage I nasopharyngeal cancer
Cancer is found in the nasopharynx (the upper part of the throat behind the nose) only.

stage I non-small cell lung cancer
Cancer is in the lung only. Stage I is divided into stages IA and IB based on the size or location of the tumor.

stage I oropharynx cancer
Cancer that is no larger than 2 centimeters (about 0.75 inch) and is confined to the oropharynx.

stage I ovarian cancer
Cancer is found in one or both of the ovaries and has not spread. Stage I is divided into stage IA, stage IB, and stage IC. In stage IA, cancer is found in a single ovary. In stage IB, cancer is found in both ovaries. In stage IC, cancer is found in one or both ovaries and one of the following is true: cancer is found on the outside surface of one or both ovaries; the capsule (outer covering) of the tumor has ruptured (broken open); or, cancer cells are found in fluid from the peritoneal cavity (the body cavity that contains most of the organs in the abdomen).

stage I pancreatic cancer
Cancer is found in the pancreas only. Stage I is divided into stage IA and stage IB based on tumor size. In stage IA, the tumor is no larger than 2 centimeters and in stage IB, the tumor is larger than 2 centimeters.

stage I prostate cancer
Cancer is found in the prostate only. It cannot be felt during a digital rectal exam and is not visible by imaging. It is usually found accidentally during surgery for other reasons, such as benign prostatic hyperplasia (a condition in which an overgrowth of prostate tissue occurs). Also called stage A1 prostate cancer.

stage I skin cancer
The tumor is no larger than 2 centimeters.

stage I testicular cancer
Stage I is divided into stage IA, stage IB, and stage IS, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IA, cancer is in the testicle and epididymis and may have spread to the inner layer of the membrane surrounding the testicle; all tumor marker levels are normal. In stage IB, the cancer is in the testicle and the epididymis and has spread to the blood or lymph vessels in the testicle; or has spread to the outer layer of the membrane surrounding the testicle; or is in the spermatic cord or the scrotum and may be in the blood or lymph vessels of the testicle; all tumor marker levels are normal. In stage IS, cancer is found anywhere within the testicle, spermatic cord, or the scrotum and either all tumor marker levels are slightly above normal; or one or more tumor marker levels are moderately above normal or high.

stage I Wilms' tumor
Cancer that is found in the kidney only and can be completely removed by surgery.

stage IA soft tissue sarcoma
Cancer in which the cells look very much like normal cells. The cancer is smaller than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IB soft tissue sarcoma
Cancer in which the cells look somewhat different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage II adrenocortical cancer
Cancer that is larger than 5 centimeters (about 2 inches) and has not spread into tissues around the adrenal gland.

stage II adult Hodgkin's lymphoma
Stage II is divided into stage II and stage IIE. In stage II, cancer is found in two or more lymph node groups on the same side of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen). In stage IIE, cancer is found in one area or organ other than the lymph nodes and in the lymph nodes near that area or organ, and may have spread to other lymph node groups on the same side of the diaphragm.

stage II adult non-Hodgkin's lymphoma
Stage II is divided into stage II and stage IIE. In stage II, cancer is found in two or more lymph node areas on the same side of the diaphragm. In stage IIE, cancer is found in an organ or tissue other than the lymph nodes and may have spread to one or more lymph nodes on the same side of the diaphragm.

stage II adult primary liver cancer
One of the following is found: (1) one tumor, which is no larger than 2 centimeters and has spread into nearby blood vessels; or (2) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver; or (3) one tumor, which is larger than 2 centimeters.

stage II anal cancer
Cancer that has spread beyond the top layer of anal tissue and is larger than 2 centimeters (about 1 inch) but has not spread to nearby organs or lymph nodes.

stage II bladder cancer
Cancer has spread to either the inner layer or outer layer of the muscle wall of the bladder.

stage II breast cancer
Stage II is divided into stage IIA and stage IIB based on tumor size and whether it has spread to the axillary lymph nodes (the lymph nodes under the arm). In stage IIA, the cancer is either no larger than 2 centimeters and has spread to the axillary lymph nodes, or between 2 and 5 centimeters but has not spread to the axillary lymph nodes. In stage IIB, the cancer is either between 2 and 5 centimeters and has spread to the axillary lymph nodes, or larger than 5 centimeters but has not spread to the axillary lymph nodes.

stage II cancer of the uterus
Cancer that has spread to the cervix.

stage II cancer of the vulva
Cancer that is found in the vulva, the space between the opening of the rectum and the vagina (perineum), or both. The tumor is larger than 2 centimeters (larger than 1 inch).

stage II cervical cancer
Cancer has spread beyond the cervix but not to the pelvic wall (the tissues that line the part of the body between the hips). Stage II is divided into stages IIA and IIB, based on how far the cancer has spread. In stage IIA, cancer has spread to the upper two thirds of the vagina but not to tissues around the uterus. In stage IIB, cancer has spread to the upper two thirds of the vagina and to the tissues around the uterus.

stage II childhood non-Hodgkin's lymphoma
Cancer is found (1) in only one area and in the lymph nodes around it; or (2) in two or more areas or lymph nodes on one side of the diaphragm (the thin muscle under the lungs that divides the chest and abdominal cavity and helps with breathing); or (3) to have started in the stomach or intestines and has been completely removed by surgery, and lymph nodes in the area may or may not contain cancer.

stage II chronic lymphocytic leukemia
There are too many lymphocytes in the blood, the liver or spleen is larger than normal, and the lymph nodes may be larger than normal.

stage II colorectal cancer
Cancer has spread outside the colon and/or rectum to nearby tissue, but it has not gone into the lymph nodes. Also called Dukes' B colorectal cancer.

stage II cutaneous T-cell lymphoma
Stage II cutaneous T-cell lymphoma may be either of the following: (1) stage IIA, in which the skin has red, dry, scaly patches but no tumors, and lymph nodes are enlarged but do not contain cancer cells; (2) stage IIB, in which tumors are found on the skin, and lymph nodes are enlarged but do not contain cancer cells.

stage II endometrial cancer
Cancer has spread from the uterus to the cervix, but not beyond the cervix. Stage II is divided into stages IIA and IIB, based on how far the disease has spread into the cervix.

stage II esophageal cancer
Stage II is divided into stage IIA and stage IIB, depending on where the cancer has spread. In stage IIA, cancer has spread to the layer of esophageal muscle or to the outer wall of the esophagus. In stage IIB, cancer may have spread to any of the first three layers of the esophagus and to nearby lymph nodes.

stage II gastric cancer
Cancer has spread (1) completely through the mucosal (innermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor, or (2) to the muscularis (middle) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor, or (3) to the serosal (outermost) layer of the stomach wall but not to lymph nodes or other organs.

stage II hypopharynx cancer
Cancer that involves more than one area of the hypopharynx or is between 2 and 4 centimeters (between 0.75 and 1.5 inches).

stage II kidney cancer
Tumor that is larger than 7 centimeters (2.75 inches).

stage II laryngeal cancer
Cancer that is found in the larynx only and has not spread to lymph nodes in the area or to other parts of the body. The exact definition of stage II depends on whether the cancer started in the supraglottis (cancer is in more than one area of the supraglottis, but the vocal cords can move normally); the glottis (cancer has spread to the supraglottis, the subglottis, or both, and the vocal cords may not be able to move normally); or the subglottis (cancer has spread to the vocal cords, which may not be able to move normally).

stage II lip and oral cavity cancer
Cancer that is larger than 2 centimeters (about 1 inch) but smaller than 4 centimeters (about 2 inches) and has not spread to lymph nodes in the area.

stage II melanoma
Stage II is divided into stages IIA, IIB, and IIC. In stage IIA, the tumor is either 1 to 2 millimeters thick, with ulceration; or 2 to 4 millimeters thick, with no ulceration. In stage IIB, the tumor is either 2 to 4 millimeters thick, with ulceration; or more than 4 millimeters thick, with no ulceration. In stage IIC, the tumor is more than 4 millimeters thick, with ulceration.

stage II mesothelioma
Cancer that has spread beyond the lining of the chest to lymph nodes in the chest.

stage II multiple myeloma
Cancer in which a moderate number of cancer cells have spread throughout the body.

stage II nasopharyngeal cancer
Stage II is divided into stage IIA and stage IIB. In stage IIA, cancer has spread from the nasopharynx (the upper part of the throat behind the nose) to the oropharynx (the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils), and/or to the nasal cavity. In stage IIB, cancer is found in the nasopharynx and has spread to lymph nodes on one side of the neck, or has spread to the area surrounding the nasopharynx and may have spread to lymph nodes on one side of the neck.

stage II non-small cell lung cancer
Cancer has spread to nearby lymph nodes or to the chest wall, the diaphragm, the mediastinal pleura (the thin membrane that covers the outside of the lungs in the area near the heart), or the parietal pericardium (the outer layer of tissue that surrounds the heart). Stage II is divided into stage IIA and stage IIB based on the size of the tumor and whether it has spread to the lymph nodes.

stage II oropharynx cancer
Tumor that is between 2 and 4 centimeters (0.75 and 1.5 inches) and is confined to the oropharynx.

stage II ovarian cancer
Cancer is found in one or both ovaries and has spread into other areas of the pelvis. Stage II is divided into stage IIA, stage IIB, and stage IIC. In stage IIA, cancer has spread to the uterus and/or the fallopian tubes. In stage IIB, cancer has spread to other tissues within the pelvis. In stage IIC, cancer has spread to the uterus and/or fallopian tubes and/or other tissue within the pelvis and cancer cells are found in fluid from the peritoneal cavity (the body cavity that contains most of the organs in the abdomen).

stage II pancreatic cancer
Stage II is divided into stage IIA and stage IIB based on where the cancer has spread. In stage IIA, cancer has spread to nearby tissues and organs but has not spread to nearby lymph nodes. In stage IIB, cancer has spread to nearby lymph nodes and may have spread to nearby tissues and organs.

stage II prostate cancer
Cancer is more advanced than in stage I, but has not spread outside the prostate. Also called stage A2, stage B1, or stage B2 prostate cancer.

stage II skin cancer
The tumor is larger than 2 centimeters.

stage II testicular cancer
Stage II is divided into stage IIA, stage IIB, and stage IIC, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IIA, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and has spread to up to 5 lymph nodes in the abdomen (none larger than 2 centimeters). In stage IIB, the cancer is anywhere within the testicle, spermatic cord, or scrotum; has spread to up to 5 lymph nodes in the abdomen (at least one of the lymph nodes is larger than 2 centimeters, but none is larger than 5 centimeters) or has spread to more than 5 lymph nodes (the lymph nodes are not larger than 5 centimeters). In stage IIC, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and has spread to a lymph node in the abdomen that is larger than 5 centimeters. All tumor marker levels are normal or slightly above normal.

stage II Wilms' tumor
Cancer has spread to tissue near the kidney, to blood vessels, or to the renal sinus (a part of the kidney through which blood and fluid enter and exit). The cancer can be completely removed by surgery.

stage IIA soft tissue sarcoma
The cancer cells look somewhat different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IIB melanoma
Melanoma in which the tumor is more than 4 millimeters thick. It has spread through the lower part of the inner layer of skin (dermis) and into subcutaneous (under the skin) tissue, but not to nearby lymph nodes.

stage IIB soft tissue sarcoma
The cancer cells look very different from normal cells. The cancer is smaller than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage IIC soft tissue sarcoma
The cancer cells look very different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) and has not spread to lymph nodes or other parts of the body.

stage III adrenocortical cancer
The cancer has spread into tissues around the adrenal gland or has spread to the lymph nodes around the adrenal gland.

stage III adult Hodgkin's lymphoma
Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIS+E. In stage III, cancer is found in lymph node groups on both sides of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen). In stage IIIE, cancer is found in lymph node groups on both sides of the diaphragm and in a nearby area or organ other than the lymph nodes. In stage IIIS, cancer is found in lymph node groups on both sides of the diaphragm and in the spleen. In stage IIIE+S, cancer is found in lymph node groups on both sides of the diaphragm, in a nearby area or organ, and in the spleen. Stage III is also divided into stage III(1) and stage III(2). In stage III(1), cancer is limited to the upper abdomen above the renal vein. In stage III(2), cancer is found in lymph nodes in the pelvis and/or near the heart.

stage III adult non-Hodgkin's lymphoma
Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIS+E. In stage III, cancer is found in lymph node areas on both sides of the diaphragm. In stage IIIE, cancer is found in lymph node areas on both sides of the diaphragm and in a nearby organ or tissue other than the lymph nodes. In stage IIIS, cancer is found in lymph node areas on both sides of the diaphragm and in the spleen. In stage IIIS+E, cancer is found in lymph node areas on both sides of the diaphragm, in a nearby organ or tissue, and in the spleen.

stage III anal cancer
Stage III anal cancer is divided into stage IIIA and IIIB. Stage IIIA anal cancer has spread to the lymph nodes around the rectum or to nearby organs such as the vagina or bladder. Stager IIIB cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum.

stage III bladder cancer
Cancer has spread from the bladder to the fatty layer of tissue surrounding it, and may have spread to the reproductive organs (prostate, uterus, vagina).

stage III breast cancer
Stage III is divided into stages IIIA and IIIB. In stage IIIA breast cancer, the cancer (1) is smaller than 5 centimeters (2 inches) and has spread to the lymph nodes in the armpit, which have grown into each other or into other structures and are attached to them; or (2) is larger than 5 centimeters and has spread to the lymph nodes in the armpit. In stage IIIB breast cancer, the cancer (1) has spread to tissues near the breast (skin, chest wall, including the ribs and the muscles in the chest); or (2) has spread to lymph nodes inside the chest wall along the breast bone.

stage III cancer of the uterus
Cancer cells have spread outside the uterus to the vagina and/or lymph nodes in the pelvis but have not spread outside the pelvis.

stage III cancer of the vulva
Cancer is found in the vulva, perineum, or both. The cancer has also spread to nearby tissues such as the lower part of the urethra (the tube through which urine passes), the vagina, and the anus (the opening of the rectum); to nearby lymph nodes; or both.

stage III cervical cancer
Cancer has spread to the lower third of the vagina and may have spread to the pelvic wall (the tissues that line the part of the body between the hips), and nearby lymph nodes. Stage III is divided into stages IIIA and IIIB, based on now far the cancer has spread. In stage IIIA, cancer has spread to the lower third of the vagina but not to the pelvic wall. In stage IIIB, cancer has spread to the pelvic wall and/or the tumor has become large enough to block the ureters (the tubes that connect the kidneys to the bladder). This blockage can cause the kidneys to enlarge or stop working. Cancer may also have spread to lymph nodes in the pelvis.

stage III childhood non-Hodgkin's lymphoma
Cancer is found (1) in areas or lymph nodes on both sides of the diaphragm (the thin muscle under the lungs that divides the chest and abdominal cavity and helps with breathing); or (2) to have started in the chest; or (3) in more than one place in the abdomen; or (4) in the area around the spine.

stage III chronic lymphocytic leukemia
There are too many lymphocytes in the blood and there are too few red blood cells. The lymph nodes, liver, or spleen may be larger than normal.

stage III colorectal cancer
Tumor cells have spread to organs and lymph nodes near the colon/rectum. Also called Dukes C colorectal cancer.

stage III cutaneous T-cell lymphoma
Nearly all of the skin is red, dry, and scaly; lymph nodes are either normal or enlarged but do not contain cancer cells.

stage III endometrial cancer
Cancer has spread beyond the uterus and cervix, but has not spread beyond the pelvis. Stage III is divided into stages IIIA, IIIB, and IIIC, based on whether cancer has spread to the connective tissue holding the uterus in place, the ovaries, fallopian tubes, vagina, and lymph nodes in the pelvis.

stage III esophageal cancer
Cancer has spread to the outer wall of the esophagus and may have spread to tissues or lymph nodes near the esophagus.

stage III gastric cancer
Stage III is divided into stage IIIA and stage IIIB depending on where the cancer has spread. In stage IIIA, cancer has spread to (1) the muscularis (middle) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor, or (2) the serosal (outermost) layer of the stomach wall and is found in 1 to 6 lymph nodes near the tumor, or (3) to organs next to the stomach but not to lymph nodes or other parts of the body. In stage IIIB, cancer has spread to the serosal (outermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor.

stage III hypopharynx cancer
The tumor is larger than 4 centimeters (about 1.5 inches) in size, has spread to a single lymph node on the same side of the neck, or both.

stage III kidney cancer
Cancer has spread to a single nearby lymph node, and/or the layer of tissue around the kidney, and/or the main blood vessels in the kidney, and/or an adrenal gland. Also called stage III renal cell cancer.

stage III laryngeal cancer
The cancer has not spread outside of the larynx, but the vocal cords cannot move normally, or the cancer has spread to tissues next to the larynx; or the cancer has spread to one lymph node on the same side of the neck as the original tumor, and the lymph node measures no larger than 3 centimeters (just over 1 inch).

stage III lip and oral cavity cancer
The cancer is larger than 4 centimeters (about 2 inches); or the cancer is any size but has spread to only one lymph node on the same side of the neck as the cancer. The lymph node that contains cancer is no larger than 3 centimeters (just over one inch).

stage III melanoma
The tumor may be of any thickness, with or without ulceration, and may have spread to 1 or more nearby lymph nodes. Stage III is divided into stages IIIA, IIIB, and IIIC. In stage IIIA, the cancer may have spread to as many as 3 nearby lymph nodes, but can be seen only with a microscope. In stage IIIB, the cancer has spread to as many as 3 lymph nodes and may not be visible without a microscope, or has satellite tumors (additional tumor growths within 1 inch of the original tumor) and has not spread to lymph nodes. In stage IIIC, the cancer either has spread to as many as 4 or more lymph nodes and can be seen without a microscope, or has lymph nodes that may not be moveable, or has satellite tumors and may have spread to lymph nodes.

stage III mesothelioma
Cancer has spread into the lung, chest wall, diaphragm (the muscle between the chest and the abdomen), the sac surrounding the heart, or the ribs. It may also have spread to other organs or tissues in the chest.

stage III multiple myeloma
A relatively large number of cancer cells have spread throughout the body. There may be one or more of the following: 1) a decrease in the number of red blood cells, causing anemia; 2) the amount of calcium in the blood is very high, because the bones are being damaged; 3) more than three bone tumors (plasmacytomas) are found; or 4) high levels of M protein are found in the blood or urine.

stage III nasopharyngeal cancer
Cancer is found in the nasopharynx (the upper part of the throat behind the nose) and has spread to lymph nodes on both sides of the neck; and/or cancer has spread to the oropharynx (the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils) and/or the nasal cavity and to lymph nodes on both sides of the neck; and/or cancer has spread to nearby bones or sinuses, with or without spreading to lymph nodes on one or both sides of the neck.

stage III non-small cell lung cancer
Cancer has spread to structures near the lung; to the lymph nodes in the area that separates the two lungs (mediastinum); or to the lymph nodes on the other side of the chest or in the lower neck. Stage III is further divided into stage IIIA (usually can be resected which is sometimes treated with surgery) and stage IIIB (usually cannot be resected which is rarely treated with surgery).

stage III oropharynx cancer
The tumor is larger than 4 centimeters (about 1.5 inches) in size and may involve a single lymph node on the same side of the neck.

stage III ovarian cancer
Cancer is found in one or both ovaries and has spread to other parts of the abdomen. Stage III is divided into stage IIIA, stage IIIB, and stage IIIC. In stage IIIA, the tumor is found in the pelvis only, but cancer cells have spread to the surface of the peritoneum. In stage IIIB, cancer has spread to the peritoneum but is not larger than 2 centimeters in diameter. In stage IIIC, cancer has spread to the peritoneum and is larger than 2 centimeters in diameter and/or has spread to lymph nodes in the abdomen. Cancer that has spread to the surface of the liver is also considered stage III disease.

stage III pancreatic cancer
Cancer has spread to the major blood vessels near the pancreas, and may have spread to nearby lymph nodes.

stage III prostate cancer
Cancer has spread beyond the outer layer of the prostate to nearby tissues and may be found in the seminal vesicles (glands that help produce semen). Also called stage C prostate cancer.

stage III skin cancer
Cancer has spread below the skin to cartilage, muscle, or bone and/or to nearby lymph nodes, but not to other parts of the body.

stage III soft tissue sarcoma
The cancer cells look very different from normal cells. The cancer is larger than 5 centimeters (about 2 inches) but has not spread to lymph nodes or other parts of the body.

stage III testicular cancer
Stage III is divided into stage IIIA, stage IIIB, and stage IIIC, and is determined after a radical inguinal orchiectomy (surgery to remove the testicle) is done. In stage IIIA, the cancer is anywhere within the testicle, spermatic cord, or scrotum; may have spread to one or more lymph nodes in the abdomen; and has spread to distant lymph nodes or to the lungs. In stage IIIB, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and may have spread to one or more nearby or distant lymph nodes or to the lungs. In stage IIIC, the cancer is anywhere within the testicle, spermatic cord, or scrotum; and may have spread to one or more nearby or distant lymph nodes or to the lungs or anywhere else in the body. The level of one or more tumor markers may range from normal to very high.

stage III Wilms' tumor
Cancer has spread to tissues near the kidney and cannot be completely removed by surgery. The cancer may have spread to blood vessels or organs near the kidney or throughout the abdomen. The cancer may also have spread to lymph nodes near the kidney.

stage IIIA adult primary liver cancer
Stage III is divided into stage IIIA and IIIB. In stage IIIA, one of the following is found: (1) one tumor, which is larger than 2 centimeters and has spread to nearby blood vessels; or (2) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver and have spread to nearby blood vessels; or (3) more than one tumor, at least one of which is larger than 2 centimeters, and all are in just one lobe of the liver and may have spread to nearby blood vessels.

stage IIIA anal cancer
Cancer has spread to the lymph nodes around the rectum or to nearby organs such as the vagina or bladder.

stage IIIA breast cancer
The tumor is either smaller than 5 centimeters and has spread to the axillary lymph nodes (the lymph nodes under the arm), and the lymph nodes are attached to each other or to other structures, or the tumor is larger than 5 centimeters and has spread to the axillary lymph nodes, and the lymph nodes may be attached to each other or to other structures.

stage IIIB adult primary liver cancer
Stage III is divided into stage IIIA and IIIB. In stage IIIB, the cancer has spread to nearby lymph nodes and one of the following is found: (1) one tumor, which may be larger than 2 centimeters; or (2) one tumor, which may be larger than 2 centimeters and has spread to nearby blood vessels; or (3) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver; or (4) more than one tumor, none of which is larger than 2 centimeters and all are in just one lobe of the liver and have spread to nearby blood vessels; or (5) more than one tumor, at least one of which is larger than 2 centimeters, and all are in just one lobe of the liver and may have spread to nearby blood vessels.

stage IIIB anal cancer
Cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum.

stage IIIB breast cancer
The tumor may be any size, has spread to the tissues near the breast (the skin or chest wall, including the ribs and muscles in the chest), and may have spread to lymph nodes within the breast or under the arm.

stage IIIC breast cancer
Cancer has spread to lymph nodes beneath the collar bone and near the neck, and may have spread to tissues near the breast (the skin or chest wall, including the ribs and muscles in the chest) and to lymph nodes within the breast or under the arm.

stage IV adrenocortical cancer
The cancer has spread to tissues or organs in the area and to lymph nodes around the adrenal cortex, or the cancer has spread to other parts of the body.

stage IV adult Hodgkin's lymphoma
The cancer is found in at least one organ other than the lymph nodes and may be in the lymph nodes near the organ(s); or the cancer is found in one organ other than the lymph nodes and has spread to lymph nodes far away from the organ.

stage IV adult non-Hodgkin's lymphoma
The cancer either (1) is found in at least one organ or tissue other than the lymph nodes and may be in nearby lymph nodes; or (2) has spread to one organ other than the lymph nodes and has spread to lymph nodes far away from that organ.

stage IV adult primary liver cancer
Stage IV is divided into stage IVA and IVB. In stage IVA, there is more than one tumor, which may have spread to nearby lymph nodes, and the tumors (1) are in both lobes of the liver; or (2) are affecting a major branch of blood vessels in the liver; or (3) have spread to nearby organs (besides the gallbladder); or (4) have broken through the lining of the peritoneal cavity. In stage IVB, the cancer has spread beyond the liver to other places in the body. The tumors may be of any size and may have also spread to nearby blood vessels and lymph nodes.

stage IV anal cancer
Cancer has spread to distant lymph nodes within the abdomen or to organs in other parts of the body.

stage IV bladder cancer
Cancer has spread from the bladder to the wall of the abdomen or pelvis. Cancer may have spread to one or more lymph nodes or to other parts of the body.

stage IV breast cancer
Cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain; or tumor has spread locally to the skin and lymph nodes inside the neck, near the collarbone.

stage IV cancer of the uterus
Cancer cells have spread to the lining of the bladder or rectum or to distant parts of the body.

stage IV cancer of the vulva
Cancer has spread beyond the urethra, vagina, and anus into the lining of the bladder (the sac that holds urine) and the bowel (intestine); or it may have spread to the lymph nodes in the pelvis or to other parts of the body.

stage IV cervical cancer
Cancer has spread to the bladder, rectum, or other parts of the body. Stage IV is divided into stages IVA and IVB. In stage IVA, cancer has spread to the bladder or rectal wall and may have spread to lymph nodes in the pelvis. In stage IVB, cancer has spread beyond the pelvis and pelvic lymph nodes to other places in the body, such as the abdomen, liver, intestinal tract, or lungs.

stage IV childhood non-Hodgkin's lymphoma
Cancer is found in the bone marrow, brain, or spinal cord. Cancer may also be found in other parts of the body.

stage IV chronic lymphocytic leukemia
There are too many lymphocytes in the blood and too few platelets. The lymph nodes, liver, or spleen may be larger than normal and there may be too few red blood cells.

stage IV colorectal cancer
Cancer may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs. Also called Dukes' D colorectal cancer.

stage IV cutaneous T-cell lymphoma
Stage IV cutaneous T-cell lymphoma may be either of the following: in stage IVA cancer, the skin is red, dry, and scaly, and the lymph nodes contain cancer cells; in stage IVB cancer, the skin is red, dry and scaly, cancer cells may be found in lymph nodes, and cancer has spread to other organs in the body.

stage IV endometrial cancer
Cancer has spread beyond the pelvis. Stage IV is divided into stages IVA and IVB, based on whether cancer has spread to the lining of the bladder (the sac that holds urine), to the bowel, or to lymph nodes or other parts of the body beyond the pelvis.

stage IV esophageal cancer
Stage IV esophageal cancer is divided into stage IVA and stage IVB, depending on where the cancer has spread. In stage IVA, cancer has spread to nearby or distant lymph nodes. In stage IVB, cancer has spread to distant lymph nodes and/or organs in other parts of the body.

stage IV gastric cancer
Cancer has spread (1) to organs next to the stomach and to at least one lymph node, or (2) to more than 15 lymph nodes, or (3) to other parts of the body.

stage IV hypopharynx cancer
The tumor has spread to nearby tissues and lymph nodes of the neck and may have spread to other parts of the body.

stage IV kidney cancer
Cancer has spread beyond the kidney to 1 or more nearby lymph nodes and/or to other organs. Also called stage IV renal cell cancer.

stage IV laryngeal cancer
The cancer has spread to tissues around the larynx, such as the pharynx or the tissues in the neck. The lymph nodes in the area may contain cancer; the cancer has spread to more than one lymph node on the same side of the neck as the cancer, to lymph nodes on one or both sides of the neck, or to any lymph node that measures more than 6 centimeters (over 2 inches); or the cancer has spread to other parts of the body.

stage IV lip and oral cavity cancer
The cancer has spread to tissues around the lip and oral cavity (the lymph nodes in the area may contain cancer); the cancer is any size and has spread to more than one lymph node on the same side of the neck as the cancer, to lymph nodes on one or both sides of the neck, or to any lymph node that is larger than 6 centimeters (larger than 2 inches); or the cancer has spread to other parts of the body.

stage IV melanoma
The tumor has spread to other organs or to lymph nodes far away from the original tumor.

stage IV mesothelioma
Cancer has spread to distant organs or tissues.

stage IV nasopharyngeal cancer
Stage IV is divided into stage IVA, stage IVB, and stage IVC. In stage IVA, cancer has spread to other areas in the head and may have spread to lymph nodes on one or both sides of the neck, and the involved lymph nodes are smaller than 6 centimeters. In stage IVB, cancer has spread to lymph nodes above the collarbone and/or the involved lymph nodes are larger than 6 centimeters. In stage IVC, cancer has spread beyond nearby lymph nodes to other parts of the body.

stage IV non-small cell lung cancer
Cancer has spread to other parts of the body or to another lobe of the lungs.

stage IV oropharynx cancer
The tumor has spread to the hard palate, tongue, or larynx, to nearby lymph nodes, and may have spread to other parts of the body.

stage IV ovarian cancer
Cancer is found in one or both ovaries and has metastasized (spread) beyond the abdomen to other parts of the body. Cancer that is found in tissues of the liver is considered stage IV disease.

stage IV pancreatic cancer
Cancer may be of any size and has spread to distant organs, such as the liver, lung, and peritoneal cavity (the body cavity that contains most of the organs in the abdomen), and may have also spread to organs and tissues near the pancreas or to lymph nodes.

stage IV prostate cancer
Cancer has metastasized (spread) to lymph nodes near or far from the prostate, or to other parts of the body, such as the bladder, rectum, bones, liver, or lungs. Metastatic prostate cancer often spreads to the bones. Also called stage D1 or stage D2 prostate cancer.

stage IV skin cancer
Cancer has spread to other parts of the body.

stage IV soft tissue sarcoma
The cancer has spread to lymph nodes in the area or other parts of the body (such as the lungs, head, or neck).

stage IV Wilms' tumor
Cancer has spread to organs further away from the kidney (such as the lungs, liver, bone, and brain).

stage IVA pancreatic cancer
Cancer has spread to organs that are near the pancreas (such as the stomach, spleen, or colon) but has not spread to distant organs (such as the liver or lungs).

stage IVB pancreatic cancer
Cancer of the pancreas in which the cancer has spread to distant organs (such as the liver or lungs).

stage V Wilms' tumor
Cancer cells are found in both kidneys.

staging  (STAY-jing)
Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

standard of care
In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with the standard of care. Also called standard therapy or best practice.

standard therapy
In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called standard of care or best practice.

statistically significant
Describes a mathematical measure of difference between groups. The difference is said to be statistically significant if it is greater than what might be expected to happen by chance alone.

staurosporine
A drug that belongs to the family of drugs called alkaloids. It is being studied in the treatment of cancer.

stavudine
A drug that belongs to the family of drugs called nucleoside analogs. It is used to treat infection caused by viruses.

stellate
Star shaped.

stem cell
A cell from which other types of cells can develop.

stem cell factor
A drug that is being studied for its ability to increase the number of stem cells in the blood.

stem cell transplantation
A method of replacing immature blood-forming cells that were destroyed by cancer treatment. The stem cells are given to the person after treatment to help the bone marrow recover and continue producing healthy blood cells.

stent
A device placed in a body structure (such as a blood vessel or the gastrointestinal tract) to provide support and keep the structure open.

stereotactic biopsy  (STAIR-ee-o-TAK-tik BY-op-see)
A biopsy procedure that uses a computer and a three-dimensional scanning device to find a tumor site and guide the removal of tissue for examination under a microscope.

stereotactic external-beam radiation
A radiation therapy technique for brain tumors that uses a rigid head frame attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic radiation therapy, stereotactic radiosurgery, and stereotaxic radiosurgery.

stereotactic injection
A procedure in which a computer and a 3-dimensional scanning device are used to inject anticancer drugs directly into a tumor.

stereotactic radiation therapy  (STAIR-ee-o-TAK-tik ray-dee-AY-shun)
A radiation therapy technique for brain tumors that uses a rigid head frame that is attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic external-beam radiation, stereotactic radiosurgery, and stereotaxic radiosurgery.

stereotactic radiosurgery  (STAIR-ee-o-TAK-tik...)
A radiation therapy technique for brain tumors that uses a rigid head frame that is attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic external-beam radiation, stereotactic radiation therapy, and stereotaxic radiosurgery.

stereotaxic radiosurgery
A radiation therapy technique for brain tumors that uses a rigid head frame that is attached to the skull. The frame is used to help aim high-dose radiation beams directly at the tumors and not at normal brain tissue. This procedure does not involve surgery. Also called stereotactic external-beam radiation, stereotactic radiation therapy, and stereotactic radiosurgery.

stereotaxis  (stair-ee-o-TAK-sis)
Use of a computer and scanning devices to create three-dimensional pictures. This method can be used to direct a biopsy, external radiation, or the insertion of radiation implants.

sterile
Unable to produce children.

steroid  (STAIR-oyd)
A type of drug used to relieve swelling and inflammation.

steroid therapy
Treatment with corticosteroid drugs to reduce swelling, pain, and other symptoms of inflammation.

STI571
A drug that is being studied for its ability to inhibit the growth of certain cancers. It interferes with a portion of the protein produced by the bcr/abl oncogene. Also called Gleevec and imatinib mesylate.

stoma  (STO-ma)
A surgically created opening from an area inside the body to the outside.

stomach
An organ that is part of the digestive system. It helps in the digestion of food by mixing it with digestive juices and churning it into a thin liquid.

stomatitis
Inflammation or irritation of the mucous membranes in the mouth.

stool
The waste matter discharged in a bowel movement; feces.

stool test
A test to check for hidden blood in the bowel movement.

streptavidin
A small bacterial protein that binds with high affinity to the vitamin biotin. This streptavidin-biotin combination can be used to link molecules such as radioisotopes and monoclonal antibodies together. These bound products have the property of being attracted to, and attaching to, cancer cells, rather than normal cells. The radiolabeled products are more easily removed from the body, thus decreasing their toxicity.

streptozocin
An anticancer drug that belongs to the family of drugs called alkylating agents.

Stromagen
A drug that is derived from a patient's stem cells (specialized cells in the bone marrow that form new blood cells) and may be given back to the patient to help restore bone marrow that has been damaged by high-dose chemotherapy.

stromal tumor  (STRO-mal)
A tumor that arises in the supporting connective tissue of an organ.

strontium
A metal often used in a radioactive form for imaging tests or as a treatment for cancer.

strontium-89
A radioactive compound that is absorbed by the bone. It is used to treat bone pain associated with prostate cancer.

study agent
A medicine, vitamin, mineral, food supplement, or a combination of them that is being tested in a clinical trial.

Sturge-Weber syndrome
SWS. A rare, congenital disorder that affects the brain, skin, and eyes. Abnormal blood vessel growth occurs in the trigeminal nerve in the face and the meninges (covering) of the brain. This abnormal growth causes red or purple skin discoloration (sometimes called a port wine stain), usually on one side of the face, and can also cause seizures, learning disabilities, and glaucoma.

SU011248
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called angiogenesis inhibitors.

SU101
An anticancer drug that works by inhibiting a cancer cell growth factor. Also called leflunomide.

SU5416
An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Also called semaxanib.

SU6668
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called angiogenesis inhibitors. Also called SU006668.

subcutaneous
Beneath the skin.

subcutaneous port
A tube surgically placed into a blood vessel and attached to a disk placed under the skin. It is used for the administration of intravenous fluids and drugs; it can also be used to obtain blood samples.

subependymal  (SUB-ep-EN-di-mal)
Below the ependyma (the membrane that lines the ventricles of the brain and the central canal of the spinal cord).

suberoylanilide hydroxamic acid
A substance that is being studied as an anticancer drug.

subglottis  (SUB-glot-is)
The lowest part of the larynx; the area from just below the vocal cords down to the top of the trachea.

subjective improvement
An improvement that is reported by the patient, but cannot be measured by the healthcare provider (for example, "I feel better").

subset analysis
In a clinical study, the evaluation of results for some but not all of the patients who participated. The selected patients have one or more characteristics in common, such as the same stage of disease or the same hormone receptor status.

subtenon
Used to describe injections through the membrane covering the muscles and nerves at the back of the eyeball.

sucralfate
A drug used to treat ulcers. It adheres to proteins at the ulcer site and forms a protective coating over the ulcer. Sucralfate is also used to treat mucositis.

sulfa drug
A type of antibiotic used to treat infection. Also called sulfonamide.

sulfonamide
A type of antibiotic used to treat infection. Also called sulfa drug.

sulfuric acid
A strong acid that, when concentrated is extemely corrosive to the skin and mucous membranes. It is used in making fertilizers, dyes, electroplating, and industrial explosives.

sulindac
A nonsteroidal anti-inflammatory drug (NSAID) that is being studied as a treatment for cancer.

sun protection factor
SPF. A scale for rating the level of sunburn protection in sunscreen products. The higher the SPF, the more sunburn protection it provides. Sunscreens with an SPF value of 2 through 11 provide minimal protection against sunburns. Sunscreens with an SPF of 12 through 29 provide moderate protection, which is adequate for most people. Those with an SPF of 30 or higher provide high protection against sunburn and are sometimes recommended for people who are highly sensitive to the sun.

sunscreen
A substance that helps protect the skin from the sun's harmful rays. Sunscreens reflect, absorb, and scatter both ultraviolet A and B radiation to provide protection against both types of radiation. Using lotions, creams, or gels that contain sunscreens can help protect the skin from premature aging and damage that may lead to skin cancer.

superficial
Affecting cells on the surface. Not invasive.

superior vena cava
The large vein that carries blood from the head, neck, arms, and chest to the heart.

superior vena cava syndrome
A condition in which a tumor presses against the superior vena cava (the large vein that carries blood from the head, neck, arms, and chest to the heart). This pressure blocks blood flow to the heart and may cause coughing, difficulty in breathing, and swelling of the face, neck, and upper arms.

supplementation
Adding nutrients to the diet.

support group
A group of people with similar disease who meet to discuss how better to cope with their disease and treatment.

supportive care
Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of supportive care is to prevent or treat as early as possible the symptoms of the disease, side effects caused by treatment of the disease, and psychological, social, and spiritual problems related to the disease or its treatment. Also called palliative care, comfort care, and symptom management.

supraclavicular lymph node
A lymph node located above the clavicle (collarbone).

supraglottic laryngectomy  (SOO-pra-GLOT-ik lair-in-JEK-tuh-mee)
An operation to remove the supraglottis, which is part of the larynx (voice box) above the vocal cords.

supraglottis  (SOO-pra-GLOT-is)
The upper part of the larynx (voice box), including the epiglottis; the area above the vocal cords.

supratentorial
Located in the upper part of the brain.

suramin
A drug used to treat bacterial and parasitic infections. It is also being studied in the treatment of cancer.

surgeon
A doctor who removes or repairs a part of the body by operating on the patient.

surgery  (SER-juh-ree)
A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

surgical castration
Surgical removal of the testicles (orchiectomy) or ovaries (oophorectomy) to stop the production of sex hormones. Decreasing the levels of hormones may stop the growth of certain cancers.

surgical oncologist
A doctor who performs biopsies and other surgical procedures in cancer patients.

survival rate
The percentage of people in a study or treatment group who are alive for a given period of time after diagnosis. This is commonly expressed as 5-year survival.

sweet elm
Ulmus fulva or Ulmus rubra. The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, gray elm, Indian elm, and red elm.

symptom
An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

symptom management
Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of symptom management is to prevent or treat as early as possible the symptoms of the disease, side effects caused by treatment of the disease, and psychological, social, and spiritual problems related to the disease or its treatment. Also called palliative care, comfort care, and supportive care.

symptomatic
Having to do with symptoms, which are signs of a condition or disease.

syncytium
A large cell-like structure formed by the joining together of two or more cells. The plural is syncytia.

syndrome  (SIN-drome)
A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the disease.

synergistic
Describes the interaction of two or more drugs such that their combined effect is greater than the sum of the individual effects seen when each drug is given alone.

syngeneic bone marrow transplantation  (SIN-juh-NAY-ik)
A procedure in which a person receives bone marrow donated by his or her healthy identical twin.

syngeneic stem cell transplantation  (SIN-juh-NAY-ik)
A procedure in which a patient receives stem cells donated by his or her healthy identical twin.

synovial membrane
A layer of connective tissue that lines the cavities of joints, tendon sheaths, and bursae (fluid-filled sacs between tendons and bones). The synovial membrane makes synovial fluid, which has a lubricating function.

synovial sarcoma
A malignant tumor that develops in the synovial membrane of the joints.

synthetic protegrin analog
A drug that may prevent oral mucositis (sores on the lining of the mouth), a side effect of some cancer treatments.

synthetic retinoid  (sin-THET-ik RET-in-oyd)
A substance related to vitamin A that is produced in a laboratory.

syringe
A small hollow tube used for injecting or withdrawing liquids. It may be attached to a needle in order to withdraw fluid from the body or inject drugs into the body.

systemic  (sis-TEM-ik)
Affecting the entire body.

systemic chemotherapy
Treatment with anticancer drugs that travel through the bloodstream, reaching and affecting cells all over the body.

systemic disease
Disease that affects the whole body.

systemic lupus erythematosus
SLE. A chronic inflammatory connective tissue disease marked by skin rashes, joint pain and swelling, inflammation of the kidneys, inflammation of the fibrous tissue surrounding the heart (i.e., the pericardium), as well as other problems. Not all affected individuals display all of these problems. Also called lupus.

systemic therapy  (sis-TEM-ik THER-a-pee)
Treatment using substances that travel through the bloodstream, reaching and affecting cells all over the body.

T

T cell
One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells. T cells also produce a number of substances that regulate the immune response.

T-3
A thyroid hormone. Also called triiodothyronine or liothyronine sodium.

T-cell depletion
Treatment to destroy T cells, which play an important role in the immune response. Elimination of T cells from a bone marrow graft from a donor may reduce the chance of an immune reaction against the recipient's tissues.

T-cell lymphoma  (lim-FO-ma)
A disease in which certain cells of the lymph system (called T lymphocytes) become cancerous.

T138067
An anticancer drug that belongs to the family of drugs called mitotic inhibitors. It inhibits the growth of cancer cells by preventing cell division.

T4N5 liposomal lotion
Enzyme lotion used in treating xeroderma pigmentosum.

T900607
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called tubulin-binding agents.

TAC-101
A substance that is being studied in the treatment of cancer. It belongs to the families of drugs called synthetic retinoids and angiogenesis inhibitors.

tacrolimus
A drug used to help reduce the risk of rejection by the body of organ and bone marrow transplants.

TAG-72 antigen
A protein/sugar complex found on the surface of many cancer cells, including breast, colon, and pancreatic cells.

talampanel
A substance that is being studied in the treatment of brain tumors and other brain disorders, such as epilepsy and Parkinson’s disease. It belongs to the family of drugs called AMPA receptor antagonists.

talaporfin sodium
A drug used in photodynamic therapy. When absorbed by cancer cells and exposed to light, the drug becomes active and kills the cancer cells.

tamoxifen  (ta-MOK-si-FEN)
A drug that is used to treat breast cancer. Tamoxifen blocks the effects of the hormone estrogen in the body. It belongs to the family of drugs called antiestrogens.

targeted therapy
A type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. A monoclonal antibody is a type of targeted therapy.

tariquidar
A substance that is being studied for its ability to overcome tumor-cell resistance to anticancer drugs. It belongs to the family of drugs called anthranilic acid derivatives. Also called XR9576.

taurolidine
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called anti-infectives.

taxane
A drug that inhibits cell growth by stopping cell division. Taxanes are used as treatments for cancer. Also called antimitotic or antimicrotubule agents or mitotic inhibitors. Docetaxel and paclitaxel are taxanes.

technetium Tc 99m dextran
A radiolabeled substance that is used in cancer diagnosis.

technetium Tc 99m sulfur colloid
A radiolabeled substance that is used to help identify sites of tumor development.

tegafur
An anticancer drug that belongs to the family of drugs called antimetabolites.

teicoplanin
A substance used to treat bacterial infections. It belongs to the family of drugs called antibiotics.

telangiectasia  (tel-AN-gee-ek-TAY-zha)
The permanent enlargement of blood vessels, causing redness in the skin or mucous membranes.

temoporfin
An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents.

temozolomide
An anticancer drug that belongs to the family of drugs called alkylating agents.

teniposide
An anticancer drug that is a podophyllotoxin derivative and belongs to the family of drugs called mitotic inhibitors.

TENS
Transcutaneous electric nerve stimulation. A technique in which mild electric currents are applied to some areas of the skin by a small power pack connected to two electrodes.

teratoma  (ter-a-TOW-ma)
A type of germ cell tumor that may contain several different types of tissue, such as hair, muscle, and bone. Teratomas occur most often in the ovaries in women, the testicles in men, and the tailbone in children. Not all teratomas are malignant.

terminal disease
Disease that cannot be cured and will cause death.

testicle  (TES-tih-kul)
One of two egg-shaped glands found inside the scrotum that produce sperm and male hormones. Also called a testis.

testimonial
Information provided by an individual who claims to have been helped or cured by a particular product. The information provided lacks the necessary elements to be evaluated in a rigorous and scientific manner and is not used in the scientific literature.

testis  (TES-tis)
One of two egg-shaped glands found inside the scrotum that produce sperm and male hormones. Also called a testicle.

testosterone  (tes-TOS-ter-own)
A hormone that promotes the development and maintenance of male sex characteristics.

tetanus toxoid
A substance that is derived from the toxin released by the bacterium that causes the disease tetanus. It is used as a vaccine to prevent tetanus or to help boost the immune response to other vaccines.

tetracycline
An antibiotic drug used to treat infection.

tetrahydrouridine
A substance that makes tumor cells more sensitive to radiation therapy and is being studied in the treatment of cancer. It belongs to the families of drugs called cytidine deaminase inhibitors, multidrug resistance modulators, and radiosensitizers.

TG4010
A substance that is being studied as an anticancer drug.

thalamus  (THAL-a-muss)
An area of the brain that helps process information from the senses and transmit it to other parts of the brain.

thalidomide
A drug that belongs to the family of drugs called angiogenesis inhibitors. It prevents the growth of new blood vessels into a solid tumor.

theophylline
A drug used to improve breathing in people who are short of breath. It belongs to the family of drugs called bronchodilators or respiratory smooth muscle relaxants.

therapeutic
Used to treat disease and help healing take place.

therapy
Treatment.

thermal ablation
A procedure using heat to remove tissue or a part of the body, or destroy its function. For example, to remove the lining of the uterus, a catheter is inserted through the cervix into the uterus, a balloon at the end of the catheter is inflated, and fluid inside the balloon is heated to destroy the lining of the uterus.

thermography
In medicine, a procedure in which a heat-sensing infrared camera is used to record the surface heat produced by different parts of the body. Abnormal tissue growth can cause temperature changes, which may show up on the thermogram. Thermography may be used to diagnose breast cancer and other tumors.

thioguanine
An anticancer drug that belongs to the family of drugs called antimetabolites.

thiotepa
An anticancer drug that belongs to the family of drugs called alkylating agents.

third-line therapy
Treatment that is given when both initial treatment (first-line therapy) and subsequent treatment (second-line therapy) don’t work, or stop working.

thoracentesis  (thor-a-sen-TEE-sis)
Removal of fluid from the pleural cavity through a needle inserted between the ribs.

thoracic  (thor-ASS-ik)
Having to do with the chest.

thoracoscopy
The use of a thin, lighted tube (called an endoscope) to examine the inside of the chest.

thoracotomy  (thor-a-KAH-toe-mee)
An operation to open the chest.

thrombocyte  (THROM-bo-site)
A blood cell that helps prevent bleeding by causing blood clots to form. Also called a platelet.

thrombocytopenia
A decrease in the number of platelets in the blood that may result in easy bruising and excessive bleeding from wounds or bleeding in mucous membranes and other tissues.

thrombohemorrhagic event
A process that involves either a blood clot or bleeding, such as a heart attack or stroke.

thrombophlebitis  (throm-bo-fleh-BY-tis)
Inflammation of a vein that occurs when a blood clot forms.

thrombopoietin
A colony-stimulating factor that stimulates the production of blood cells, especially platelets, during chemotherapy. It is a cytokine that belongs to the family of drugs called hematopoietic (blood forming) agents.

thrombosis  (throm-BOW-sis)
The formation or presence of a blood clot inside a blood vessel.

thrush
A condition in which Candida albicans, a type of yeast, grows out of control in moist skin areas of the body. It is usually a result of a weakened immune system, but can be a side effect of chemotherapy or treatment with antibiotics. Thrush usually affects the mouth (oral thrush); however, rarely, it spreads throughout the entire body. Also called Candidiasis or Candidosis.

thymidine
A chemical compound found in DNA. Also used as treatment for mucositis.

thymidylate synthase inhibitor
A drug that blocks DNA synthesis and may prevent tumor cell growth. It is being studied as a treatment for cancer.

thymoma
A tumor of the thymus, an organ that is part of the lymphatic system and is located in the chest, behind the breastbone.

thymus
An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.

thyroglobulin  (THIGH-roe-GLOB-yu-lin)
The form that thyroid hormone takes when stored in the cells of the thyroid. If the thyroid has been removed, thyroglobulin should not show up on a blood test. Doctors measure thyroglobulin level in blood to detect thyroid cancer cells that remain in the body after treatment.

thyroid  (THIGH-royd)
A gland located beneath the voice box (larynx) that produces thyroid hormone. The thyroid helps regulate growth and metabolism.

thyroid follicular cell  (THIGH-royd fo-LIK-yu-ler)
A type of cell in the thyroid. Thyroid follicular cells make thyroid hormone.

thyroid gland  (THIGH-royd)
A gland located beneath the voice box (larynx) that produces thyroid hormone. The thyroid helps regulate growth and metabolism.

thyroid hormone
The thyroid gland makes T3 (triiodothyronine) and T4 (thyroxine), which together are considered thyroid hormone. T3 and T4 have identical effects on cells. Thyroid hormone affects heart rate, blood pressure, body temperature, and weight. T3 and T4 are stored as thyroglobulin, which can be converted back into T3 and T4.

thyroid-stimulating hormone
TSH. A hormone produced by the pituitary gland. TSH stimulates the release of thyroid hormone from thyroglobulin. It also stimulates the growth of thyroid follicular cells. An abnormal TSH level may mean that the thyroid hormonal regulation system is out of control, usually as a result of a benign condition (hyperthyroidism or hypothyroidism).

thyroidectomy  (thigh-roid-EK-toe-mee)
Surgery to remove part or all of the thyroid.

tiazofurin
An anticancer drug being studied to stop cell growth.

time to progression
A measure of time after a disease is diagnosed (or treated) until the disease starts to get worse.

tin ethyl etiopurpurin
An anticancer drug that is also used in cancer prevention. It belongs to the family of drugs called photosensitizing agents. Also called SnET2.

tin Sn 117m DTPA
A radioactive chemical being studied to treat bone pain associated with cancer.

tinidazole
A drug used to treat protozoal infections, such as amebiasis, giardiasis, and trichomoniasis. It belongs to a family of drugs called antiprotozoal agents. Tinidazole is also being evaluated in the treatment of Helicobacter pylori infections in people with low-grade gastric lymphoma.

tipifarnib
An anticancer drug that inhibits the transformation of normal cells to cancer cells. It belongs to the family of drugs called enzyme inhibitors. Also called R115777.

tirapazamine
A drug that makes tumor cells more sensitive to radiation therapy.

tissue  (TISH-oo)
A group or layer of cells that are alike and that work together to perform a specific function.

tissue flap reconstruction
A type of breast reconstruction in which a flap of tissue is surgically moved from another area of the body to the chest, and formed into a new breast mound.

tissue plasminogen activator
tPA. A protein that is made by the body and that helps dissolve blood clots. It can also be made in the laboratory and is used in the treatment of heart attack and stroke. It is also being studied in the treatment of cancer. tPA belongs to the family of drugs called systemic thrombolytic agents. Also called recombinant tissue plasminogen activator (r-tPA), Activase, and Alteplase.

TLK286
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called glutathione analogs.

TM
Transcendental meditation. A mental technique used to promote relaxation, reduce stress, and improve quality of life.

TNF
Tumor necrosis factor. A type of biological response modifier (a substance that can improve the body's natural response to disease).

TNFerade
A gene therapy product that is being studied as a treatment for cancer in combination with radiation therapy.

TNM staging system
A system for describing the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).

TNP-470
A drug that belongs to the family of drugs called angiogenesis inhibitors. It prevents the growth of new blood vessels into a solid tumor.

tocladesine
A substance that is being studied as an anticancer drug. It is an analog of a substance that occurs naturally in the body (cyclic adenosine monophosphate).

tomography  (tuh-MAH-gra-fee)
A series of detailed pictures of areas inside the body; the pictures are created by a computer linked to an x-ray machine.

tonsil
One of two small masses of lymphoid tissue on either side of the throat.

topical
On the surface of the body.

topical chemotherapy  (kee-mo-THER-a-pee)
Treatment with anticancer drugs in a lotion or cream applied to the skin.

topoisomerase inhibitor
An anticancer drug. The topoisomerase enzymes are responsible for the arrangement and rearrangement of DNA in the cell and for cell growth and replication. Inhibiting these enzymes may kill cancer cells or stop their growth.

topotecan
An anticancer drug that belongs to the family drugs called topoisomerase inhibitors.

toremifene
An anticancer drug that belongs to the family of drugs called antiestrogens. Toremifene blocks the effect of the hormone estrogen in the body. It may help control some cancers from growing, and it may delay or reduce the risk of cancer recurrence.

tositumomab
A monoclonal antibody that is used in the treatment of certain types of non-Hodgkin's lymphoma. When tositumomab and iodine I 131 tositumomab (a form of tositumomab that has been chemically changed by adding radioactive iodine) are given together, the combination is called the Bexxar regimen.

total androgen blockade
Therapy used to eliminate male sex hormones (androgens) in the body. This may be done with surgery, hormonal therapy, or a combination.

total estrogen blockade
Therapy used to eliminate estrogen in the body. This may be done with surgery, radiation therapy, chemotherapy, or a combination of these procedures.

total hysterectomy
Surgery to remove the entire uterus, including the cervix. Sometimes, not all of the cervix is removed. Also called complete hysterectomy.

total laryngectomy  (LAIR-in-JEK-tuh-mee)
An operation to remove all of the larynx (voice box).

total mastectomy  (mas-TEK-toe-mee)
Removal of the breast. Also called simple mastectomy.

total nodal irradiation
Radiation therapy to the mantle field, the spleen, the lymph nodes in the upper abdomen, and the lymph nodes in the pelvic area.

total pancreatectomy
Surgery to remove the entire pancreas. Part of the stomach, part of the small intestine, the common bile duct, gallbladder, spleen, and nearby lymph nodes also are removed.

total parenteral nutrition
TPN. Intravenous (into a vein) feeding that provides necessary nutrients when a person is unable to eat normally.

total-body irradiation
Radiation therapy to the entire body. Usually followed by bone marrow or peripheral stem cell transplantation.

totipotent
Having to do with cells that are able to develop into any type of cell found in the body.

toxic
Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

toxin
A poison produced by certain animals, plants, or bacteria.

TP-38 immunotoxin
A substance that combines a protein that binds to certain tumor cells with a bacterial toxin that kills tumor cells. It is being studied in the treatment of brain tumors.

tPA
Tissue plasminogen activator. A protein that is made by the body and that helps dissolve blood clots. It can also be made in the laboratory and is used in the treatment of heart attack and stroke. It is also being studied in the treatment of cancer. tPA belongs to the family of drugs called systemic thrombolytic agents. Also called recombinant tissue plasminogen activator (r-tPA), Activase, and Alteplase.

TPA
12-O-tetradecanoylphorbol-13-acetate. A drug that is being studied as a treatment for hematologic cancer.

trace element
A chemical found in very small amounts in a given substance. Organisms need certain trace elements to survive.

tracer
A substance (such as a radioisotope) used in imaging procedures.

trach tube
A 2-inch- to 3-inch-long curved metal or plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open. Also called a tracheostomy tube.

trachea  (TRAY-kee-uh)
The airway that leads from the larynx to the lungs. Also called the windpipe.

tracheoesophageal puncture  (TRAY-kee-o-eh-SOF-uh-JEE-al PUNK-chur)
A small opening made by a surgeon between the esophagus and the trachea. A valve keeps food out of the trachea but lets air into the esophagus for esophageal speech.

tracheostomy  (TRAY-kee-AHS-toe-mee)
Surgery to create an opening (stoma) into the windpipe. The opening itself may also be called a tracheostomy.

tracheostomy button  (TRAY-kee-AHS-toe-mee)
A 0.5-inch- to 1.5-inch-long plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open.

tracheostomy tube  (TRAY-kee-AHS-tuh-mee toob)
A 2-inch- to 3-inch-long curved metal or plastic tube placed in a surgically created opening (tracheostomy) in the windpipe to keep it open. Also called a trach ("trake") tube.

transabdominal ultrasound
A procedure used to examine the organs in the abdomen. The ultrasound device is pressed firmly against the skin of the abdomen. Sound waves from the device bounce off tissues and create echoes. A computer uses the echoes to make a picture called a sonogram.

transcendental meditation
TM. A mental technique used to promote relaxation, reduce stress, and improve quality of life.

transcutaneous electric nerve stimulation
TENS. A technique in which mild electric currents are applied to some areas of the skin by a small power pack connected to two electrodes.

transdermal
Through the skin.

transformation
The change that a normal cell undergoes as it becomes malignant.

transfusion  (trans-FYOO-zhun)
The infusion of components of blood or whole blood into the bloodstream. The blood may be donated from another person, or it may have been taken from the person earlier and stored until needed.

transitional cell
A cell that varies in shape depending on whether the tissue is being stretched. Transitional cells may be stretched without breaking apart. They line hollow organs such as the bladder.

transitional cell carcinoma
A type of cancer that develops in the lining of the bladder, ureter, or renal pelvis (the part of the kidney that collects, holds, and drains urine).

transperineal biopsy
A procedure in which a sample of tissue is removed from the prostate for examination under a microscope. The sample is removed with a thin needle that is inserted through the skin between the scrotum and rectum and into the prostate.

transplant surgeon
A doctor who specializes in transplantation surgery. The surgeon replaces a patient's organ with an organ from another person.

transplantation
The replacement of tissue with tissue from the person’s own body or from another person.

transrectal biopsy  (TRANS-REK-tal BY-op-see)
A procedure in which a sample of tissue is removed from the prostate using a thin needle that is inserted through the rectum and into the prostate. Transrectal ultrasound (TRUS) is usually used to guide the needle. The sample is examined under a microscope to see if it contains cancer.

transrectal ultrasound  (TRANS-REK-tal)
TRUS. A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. TRUS is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called endorectal ultrasound.

transurethral biopsy
A procedure in which a sample of tissue is removed from the prostate for examination under a microscope. A thin, lighted tube is inserted through the urethra into the prostate, and a small piece of tissue is removed with a cutting loop.

transurethral needle ablation
A procedure that is used to treat benign prostatic hypertrophy (BPH). A small probe that gives off low-level radiofrequency energy is inserted through the urethra into the prostate. The energy from the probe heats and destroys the abnormal prostate tissue without damaging the urethra. Also called transurethral radiofrequency ablation.

transurethral resection  (TRANZ-yoo-REE-thral ree-SEK-shun)
Surgery performed with a special instrument inserted through the urethra. Also called TUR.

transurethral resection of the prostate  (TRANZ-yoo-REE-thral ree-SEK-shun)
Surgical procedure to remove tissue from the prostate using an instrument inserted through the urethra. Also called TURP.

transvaginal ultrasound
A procedure used to examine the vagina, uterus, fallopian tubes, ovaries, and bladder. An instrument is inserted into the vagina, and sound waves bounce off organs inside the pelvic area. These sound waves create echoes, which a computer uses to create a picture called a sonogram. Also called TVS.

trastuzumab  (tras-TOO-zuh-mab)
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells. Trastuzumab blocks the effects of the growth factor protein HER2, which transmits growth signals to breast cancer cells.

Traumeel® S
A substance that contains minerals and extracts of 14 plants, including belladonna, arnica, St. John's wort, and Echinacea. It is being studied as a mouth rinse treatment for oral mucositis (painful mouth sores) caused by cancer therapy. It is known as a homeopathic remedy.

treatment field
In radiation therapy, the place on the body where the radiation beam is aimed.

treosulfan
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called alkylating agents.

tretinoin
A form of vitamin A that is used in the treatment of acne. It is also being studied in cancer prevention and as a treatment for acute promyelocytic leukemia, usually in combination with other drugs. Also called all-trans retinoic acid.

triacetyluridine
A substance that is being studied for its ability to protect against the gastrointestinal side effects caused by fluorouracil. It is a precursor of uridine, which is a component of RNA.

triamcinolone  (try-am-SIN-oh-lone)
A substance that is being studied for the prevention of nonmelanoma skin cancer. It is an anti-inflammatory drug that is applied to the skin to relieve irritation, rashes, and infections. It belongs to the family of drugs called topical corticosteroids.

Triapine®
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called ribonucleotide reductase inhibitors. Also called 3-aminopyridine-2-carboxaldehyde thiosemicarbazone and 3-AP.

tributyrin
A triglyceride drug that may inhibit cell growth and induce cell differentiation. Differentiating agents may be effective in changing cancer cells back into normal cells.

trichothiodystrophy
A hereditary condition characterized by sparse and brittle hair, short stature, and mental retardation.

trigeminal nerve
The main sensory nerve of the head and face, and the motor nerve of the muscles used in chewing. Also called the fifth cranial nerve.

triiodothyronine
A thyroid hormone. Also called liothyronine sodium or T-3.

trimethoprim-sulfamethoxazole
An antibiotic drug used to treat infection and prevent pneumocystis carinii pneumonia.

trimetrexate glucuronate
A drug that belongs to the family of drugs called antimetabolites. It is used in the treatment of pneumocystis carinii pneumonia and is being studied in the treatment of cancer.

triptorelin
A hormonal anticancer drug that belongs to the family of drugs called gonadotropin-releasing analogs.

troglitazone
A drug used in diabetes treatment that is being studied for its effect on reducing the risk of cancer cell growth in fat tissue.

tropisetron
A substance that is used to prevent nausea and vomiting caused by chemotherapy.

troxacitabine
A drug being studied for use as an anticancer agent.

TRUS
Transrectal ultrasound. A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. TRUS is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called endorectal ultrasound.

tubal ligation  (TOO-bul lye-GAY-shun)
An operation to tie the fallopian tubes closed. This procedure prevents pregnancy by blocking the passage of eggs from the ovaries to the uterus.

tuberous sclerosis
A genetic disorder in which benign (noncancerous) tumors form in the kidneys, brain, eyes, heart, lungs, and skin. This disease can cause seizures, mental disabilities, and different types of skin lesions.

tubulovillous adenoma
A type of polyp that grows in the colon and other places in the gastrointestinal tract and sometimes in other parts of the body. These adenomas may become malignant (cancerous).

tumor  (TOO-mer)
A mass of excess tissue that results from abnormal cell division. Tumors perform no useful body function. They may be benign (not cancerous) or malignant (cancerous).

tumor antigen vaccine
A vaccine made of tumor antigens (proteins isolated from tumor cells).

tumor board review
A treatment planning approach in which a number of doctors who are experts in different specialties (disciplines) review and discuss the medical condition and treatment options of a patient. In cancer treatment, a tumor board review may include that of a medical oncologist (who provides cancer treatment with drugs), a surgical oncologist (who provides cancer treatment with surgery), and a radiation oncologist (who provides cancer treatment with radiation). Also called a multidisciplinary opinion.

tumor burden
Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor load.

tumor debulking
Surgically removing as much of the tumor as possible.

tumor infiltrating lymphocyte
A white blood cell that has left the bloodstream and migrated into a tumor.

tumor load
Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor burden.

tumor marker
A substance sometimes found in the blood, other body fluids, or tissues. A high level of tumor marker may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (prostate cancer). Also called biomarker.

tumor model
A type of animal model which can be used to study the development and progression of diseases and to test new treatments before they are given to humans. Animals with transplanted human cancers or other tissues are called xenograft models.

tumor necrosis factor  (TOO-mer ne-KRO-sis)
A type of biological response modifier (a substance that can improve the body's natural response to disease). Three types of tumor necrosis factor have been identified: alpha, beta, and gamma. Tumor necrosis factor seems to play a role in the breakdown of cancer cells.

tumor suppressor gene  (TOO-mer)
Genes in the body that can suppress or block the development of cancer.

tumor-derived
Taken from an individual's own tumor tissue; may be used in the development of a vaccine that enhances the body's ability to build an immune response to the tumor.

tumor-specific antigen
A protein or other molecule that is unique to cancer cells or is much more abundant in them. These molecules are usually found in the plasma (outer) membrane, and they are thought to be potential targets for immunotherapy or other types of anticancer treatment.

TUR
Surgery performed with a special instrument inserted through the urethra. Also called transurethral resection.

Turkish rhubarb
Rheum palmatum or Rheum officinale. The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Also called rhubarb, da-huang, Chinese rhubarb, and Indian rhubarb.

TURP
Surgical procedure to remove tissue from the prostate using an instrument inserted through the urethra. Also called transurethral resection of the prostate.

TVS
A procedure used to examine the vagina, uterus, fallopian tubes, and bladder. An instrument is inserted into the vagina, and sound waves bounce off organs inside the pelvic area. These sound waves create echoes, which a computer uses to create a picture called a sonogram. Also called transvaginal ultrasound.

tympanites
Swelling of the abdomen caused by gas in the intestines or peritoneal cavity. Also called meteorism.

tyrosinase peptide
A tumor-specific antigen used in the development of cancer vaccines.

tyrosine kinase inhibitor
A drug that interferes with cell communication and growth and may prevent tumor growth. Some tyrosine kinase inhibitors are used to treat cancer.

TZT-1027
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called tubulin inhibitors. Also called soblidotin.

U

ubiquinone
A substance found in most tissues in the body, and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, Q10, CoQ10, and vitamin Q10.

UCN-01
An anticancer drug that belongs to the family of drugs called staurosporine analogs.

UGT1A1
A substance that is being studied as a treatment for cancer. It is an enzyme produced by the liver and intestine.

ulceration
The formation of a break on the skin or on the surface of an organ. An ulcer forms when the surface cells die and are cast off. Ulcers may be associated with cancer and other diseases.

ulcerative colitis
Chronic inflammation of the colon that produces ulcers in its lining. This condition is marked by abdominal pain, cramps, and loose discharges of pus, blood, and mucus from the bowel.

ultrasonogram
A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called a sonogram.

ultrasonography  (UL-tra-son-OG-ra-fee)
A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasound.

ultrasound
A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

ultrasound energy
A form of therapy being studied as an anticancer treatment. Intensified ultrasound energy can be directed at cancer cells to heat them and kill them.

ultrasound transducer
A device that produces sound waves that bounce off body tissues and make echoes. The transducer also receives the echoes and sends them to a computer that uses them to create a picture called a sonogram. Transducers (also called probes) come in different shapes and sizes for use in making pictures of different parts of the body. The transducer may be passed over the surface of the body or inserted into an opening such as the rectum or vagina.

ultrasound-guided biopsy  (BY-op-see)
A biopsy procedure that uses an ultrasound imaging device to find an abnormal area of tissue and guide its removal for examination under a microscope.

ultraviolet radiation  (ul-tra- VYE-o-let ray-dee-AY-shun)
UV radiation. Invisible rays that are part of the energy that comes from the sun. UV radiation also comes from sun lamps and tanning beds. UV radiation can damage the skin and cause melanoma and other types of skin cancer. UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB rays. UVB rays are more likely than UVA rays to cause sunburn, but UVA rays pass deeper into the skin. Scientists have long thought that UVB radiation can cause melanoma and other types of skin cancer. They now think that UVA radiation also may add to skin damage that can lead to skin cancer and cause premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter both kinds of UV radiation.

ultraviolet radiation therapy
A form of radiation used in the treatment of cancer.

umbilical cord blood
Blood from the umbilical cord of a newborn baby. This blood contains high concentrations of stem cells (cells from which all blood cells develop).

umbilical cord blood transplantation
The injection of umbilical cord blood to restore an individual's own blood production system suppressed by anticancer drugs, radiation therapy, or both. It is being studied in the treatment of cancer and severe blood disorders such as aplastic anemia. Cord blood contains high concentrations of stem cells needed to produce new blood cells.

uncontrolled study
A clinical study that lacks a comparison (i.e., a control) group.

unconventional cancer treatments
Approaches that use substances or methods of treating cancer that have not been shown to be effective by accepted scientific methods, such as carefully designed clinical trials.

undescended testicles
A condition in which one or both testicles fail to move from the abdomen, where they develop before birth, into the scrotum. Undescended testicles may increase the risk for development of testicular cancer. Also called cryptorchidism.

undifferentiated
A term used to describe cells or tissues that do not have specialized ("mature") structures or functions. Undifferentiated cancer cells often grow and spread quickly.

unilateral
Having to do with one side of the body.

unilateral salpingo-oophorectomy
Surgery to remove the ovary and fallopian tube on one side of the body.

unresectable
Unable to be removed with surgery.

unresectable gallbladder cancer
Cancer that has spread to the tissues around the gallbladder (such as the liver, stomach, pancreas, intestine, or lymph nodes in the area) and cannot be surgically removed.

unsealed internal radiation therapy
Radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity, or by swallowing it. This substance is not sealed in a container.

upper GI series
A series of x-rays of the upper digestive (gastrointestinal, or GI) system that are taken after a person drinks a barium solution, which outlines the digestive organs on the x-rays.

urachus  (YOU-rah-kus)
A fibrous cord that connects the urinary bladder to the umbilicus (navel). The urachus is formed as the allantoic stalk during fetal development and lasts through life. Also called the median umbilical ligament.

uracil
An anticancer drug that belongs to the family of drugs called alkylating agents.

urea nitrogen
A chemical in the blood produced by the breakdown of protein. Urea nitrogen is removed from the blood by the kidneys. Blood urea nitrogen (BUN) tests are sometimes done to see how well the kidneys are working.

ureter  (yoo-REE-ter)
The tube that carries urine from the kidney to the bladder.

ureteronephrectomy
Surgery to remove a kidney and its ureter. Also called nephroureterectomy.

ureteroscopy
An examination of the inside of the kidney and ureter. A thin, lighted tube (called a ureteroscope) is passed through the urethra into the bladder, ureter, and renal pelvis (part of the kidney that collects, holds, and drains urine).

urethra  (yoo-REE-thra)
The tube through which urine leaves the body. It empties urine from the bladder.

urinalysis
A test that determines the content of the urine.

urinary
Having to do with urine or the organs of the body that produce and get rid of urine.

urinary incontinence  (YOO-rin-air-ee in-KAHN-tih-nens)
Inability to hold urine in the bladder.

urinary tract  (YOO-rin-air-ee)
The organs of the body that produce and discharge urine. These include the kidneys, ureters, bladder, and urethra.

urine  (YOO-rin)
Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.

urine cytology
Tests performed on cells in urine to detect disease.

urokinase
A drug that dissolves blood clots or prevents them from forming.

urologic oncologist  (yoor-uh-LAHJ-ik on-KOL-o-jist)
A doctor who specializes in treating cancers of the urinary system.

urologist  (yoo-RAHL-o-jist)
A doctor who specializes in diseases of the urinary organs in females and the urinary and sex organs in males.

urostomy  (yoo-RAHS-toe-mee)
An operation to create an opening from inside the body to the outside, making a new way to pass urine.

urothelium
The lining of the ureters, bladder, and urethra.

ursodiol  (ur-so-DYE-ole)
A drug that is used to dissolve gallstones in people who can’t have surgery to remove them. It is also being studied in the prevention of colorectal cancer. Ursodiol belongs to the family of drugs called anticholelithics.

uterus  (YOO-ter-us)
The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a fetus develops. Also called the womb.

UV radiation
Ultraviolet radiation. Invisible rays that are part of the energy that comes from the sun. UV radiation also comes from sun lamps and tanning beds. UV radiation can damage the skin and cause melanoma and other types of skin cancer. UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB rays. UVB rays are more likely than UVA rays to cause sunburn, but UVA rays pass deeper into the skin. Scientists have long thought that UVB radiation can cause melanoma and other types of skin cancer. They now think that UVA radiation also may add to skin damage that can lead to skin cancer and cause premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter both kinds of UV radiation.

UVA radiation
A type of ultraviolet (UV) radiation. UV rays are invisible rays that are part of the energy that comes from the sun. UVA radiation also comes from sun lamps and tanning beds. Scientists think that UVA radiation may cause skin damage that can lead to skin cancer and premature aging. For this reason, skin specialists recommend that people use sunscreens that reflect, absorb, or scatter ultraviolet radiation.

UVB radiation
A type of ultraviolet (UV) radiation. UV rays are invisible rays that are part of the energy that comes from the sun. UVB radiation causes sunburn, and scientists have long thought that it can cause melanoma and other types of skin cancer. Skin specialists recommend that people use sunscreens that reflect, absorb, or scatter ultraviolet radiation.

V

vaccinated
Treated with a vaccine.

vaccination
Treatment with a vaccine.

vaccine
A substance or group of substances meant to cause the immune system to respond to a tumor or to microorganisms, such as bacteria or viruses. A vaccine can help the body recognize and destroy cancer cells or microorganisms.

vaccine adjuvant
A substance added to a vaccine to improve the immune response so that less vaccine is needed.

vaccinia CEA vaccine
A cancer vaccine containing the carcinoembryonic antigen (CEA) gene.

vagina  (vah-JYE-na)
The muscular canal extending from the uterus to the exterior of the body. Also called the birth canal.

vaginal
Having to do with the vagina (the birth canal).

valacyclovir
A substance that is being studied in the prevention of fungal, bacterial, and viral infections in patients undergoing donor stem cell transplantation with cells that are infected with cytomegalovirus. It belongs to the family of drugs called antivirals.

valdecoxib
A substance that is being studied as a treatment for pain and other side effects of cancer therapy. It belongs to the family of drugs called COX-2 inhibitors.

valerian
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called garden valerian, Indian valerian, Pacific valerian, Mexican valerian, garden heliotrope, and Valerianae radix.

Valeriana officinalis
Valerian. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called garden valerian, Indian valerian, Pacific valerian, Mexican valerian, garden heliotrope, and Valerianae radix.

Valerianae radix
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, garden valerian, Indian valerian, Pacific valerian, Mexican valerian, and garden heliotrope.

valganciclovir
An antiviral agent that is being studied as a treatment for AIDS-related cytomegalovirus. It is changed in the body to ganciclovir.

valproic acid  (val-PRO-ik acid)
A drug used to treat epileptic seizures and bipolar disorder and to prevent migraine headaches. It is also being studied in the treatment of Kaposi's sarcoma. It belongs to the families of drugs called anticonvulsants, antimanics, and migraine headache prophylactics.

vancomycin
An antibiotic drug used to fight resistant bacterial infections.

vapreotide
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called somatostatin analogs.

varicose vein
A condition in which a vein, most often in the legs, becomes permanently enlarged, twisted, and painful. This may be caused by valves in the vein that don’t work properly or by weakness in the vein walls.

vas deferens
A coiled tube that carries the sperm out of the testes.

vascular endothelial growth factor
VEGF. A substance made by cells that stimulates new blood vessel formation.

vasectomy  (vas-EK-toe-mee)
An operation to cut or tie off the two tubes that carry sperm out of the testicles.

vasomotor
Affecting the narrowing and widening of the blood vessels.

VEGF
Vascular endothelial growth factor. A substance made by cells that stimulates new blood vessel formation.

VEGF Trap
A substance that blocks the action of vascular endothelial growth factor (VEGF), and prevents the growth of new blood vessels into a tumor. It belongs to the family of drugs called angiogenesis inhibitors.

venipuncture
The puncture of a vein with a needle for the purpose of drawing blood. Also called phlebotomy.

venlafaxine
An antidepressant drug that is being evaluated for the treatment of hot flashes in women who have breast cancer.

ventricle  (VEN-trih-kul)
A fluid-filled cavity in the heart or brain.

Viagra
A substance that is used to treat erectile dysfunction. Viagra relaxes the smooth muscle of the penis to allow increased blood flow and erection. It belongs to the family of drugs called phosphodiesterase inhibitors. Also called sildenafil.

video-assisted resection
Surgery that is aided by the use of a video camera that projects and enlarges the image on a television screen. Also called video-assisted surgery.

video-assisted surgery
Surgery that is aided by the use of a video camera that projects and enlarges the image on a television screen. Also called video-assisted resection.

villous adenoma
A type of polyp that grows in the colon and other places in the gastrointestinal tract and sometimes in other parts of the body. These adenomas may become malignant (cancerous).

villus
A tiny hair-like projection, often on the surface of mucous membranes. The plural is villi.

vinblastine
An anticancer drug that belongs to the family of plant drugs called vinca alkaloids. It is a mitotic inhibitor.

vinca alkaloid
An anticancer drug that inhibits cancer cell growth by stopping cell division. It is also called an antimitotic or antimicrotubule agent, or a mitotic inhibitor.

vincristine
An anticancer drug that belongs to the family of plant drugs called vinca alkaloids.

vindesine
An anticancer drug that belongs to the family of plant drugs called vinca alkaloids.

vinorelbine
An anticancer drug that belongs to the family of plant drugs called vinca alkaloids.

vinyl chloride  (VINE-uhl KLOR-ide)
A substance used to make plastics. Exposure to vinyl chloride may increase the risk of developing liver, brain, and lung cancers; lymphoma; and leukemia.

viral
Having to do with a virus.

viral vector
A type of virus used in cancer therapy. The virus is changed in the laboratory and cannot cause disease. Viral vectors produce tumor antigens (proteins found on a tumor cell) and can stimulate an antitumor immune response in the body. Viral vectors may also be used to carry genes that can change cancer cells back to normal cells.

virtual colonoscopy  (ko-lun-AHS-ko-pee)
A method under study to examine the colon by taking a series of x-rays (called a CT scan) and using a high-powered computer to reconstruct 2-D and 3-D pictures of the interior surfaces of the colon from these x-rays. The pictures can be saved, manipulated to better viewing angles, and reviewed after the procedure, even years later. Also called computed tomography colography.

virulence
The ability of a microorganism to cause damage to its host.

virulent
Refers to the ability of a virus or a bacterium to cause damage to its host.

Virulizin
A substance that activates some types of immune system cells, and is being studied as a treatment for cancer. It belongs to the family of drugs called biological therapy agents.

virus  (VYE-rus)
A microorganism that can infect cells and cause disease.

virus replication cycle
The reproduction cycle of viruses. A replication cycle begins with the infection of a host cell and ends with the release of mature progeny virus particles.

virus-neutralizing antibody
An antibody that binds to a virus and interferes with its ability to infect a cell.

viscera
The soft internal organs of the body, including the lungs, the heart, and the organs of the digestive, excretory, and reproductive systems.

visceral
Having to do with the viscera, which are the soft internal organs of the body, including the lungs, the heart, and the organs of the digestive, excretory, reproductive, and circulatory systems.

viscotoxin
A member of a group of small proteins produced by mistletoe plants that are able to kill cells and may stimulate the immune system.

visilizumab
A monoclonal antibody that binds to CD3 (a substance found on T-cells) and that is being studied as a treatment for graft-versus-host disease (GVHD). It belongs to the family of drugs called monoclonal antibodies.

visual pathway glioma
A rare, slow-growing tumor of the eye.

vital
Necessary to maintain life. Breathing is a vital function.

vitamin
A key nutrient that the body needs in small amounts to grow and stay strong. Examples are vitamins A, C, and E.

vitamin A
A substance used in cancer prevention. It belongs to the family of drugs called retinoids.

vitamin E
A substance used in cancer prevention. It belongs to the family of drugs called tocopherols.

vitamin K
A substance that promotes the clotting of blood.

vitamin Q10
A substance found in most tissues in the body, and in many foods. It can also be made in the laboratory. It is used by the body to produce energy for cells, and as an antioxidant. It is being studied in the treatment of cancer and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, Q10, CoQ10, and ubiquinone.

VNP20009
A genetically modified Salmonella bacterium that is injected into the tumor. It is being studied for its ability to shrink solid tumors.

VNP40101M
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called alkylating agents.

vocal cord  (VOH-kul kord)
One of two small bands of muscle within the larynx that vibrates to produce the voice.

von Hippel-Lindau syndrome
A rare inherited disorder in which blood vessels grow abnormally in the eyes, brain, spinal cord, adrenal glands, or other parts of the body. People with von Hippel-Lindau syndrome have a higher risk of developing some types of cancer.

voriconazole
A drug that treats infections caused by fungi.

vorozole
A hormone therapy drug used to decrease the production of estrogen.

vulva
The external female genital organs, including the clitoris, vaginal lips, and the opening to the vagina.

vulvar cancer
Cancer of the vulva (the external female genital organs, including the clitoris, vaginal lips, and the opening to the vagina).

VX 853
A drug being studied to make cancer cells less resistant to the effects of chemotherapy.

VX-710
A drug being studied to make cancer cells less resistant to the effects of chemotherapy.

W

Waldenstrom's macroglobulinemia
An indolent (slowly progressing) type of non-Hodgkin’s lymphoma marked by abnormal levels of IgM antibodies in the blood and an enlarged liver, spleen, or lymph nodes. Also called lymphoplasmacytic lymphoma.

warfarin
A drug that prevents blood from clotting. It belongs to the family of drugs called anticoagulants (blood thinners).

wart
A raised growth on the surface of the skin or other organ.

watchful waiting
Closely monitoring a patient's condition but withholding treatment until symptoms appear or change. Also called observation.

watercress
Nasturtium officinale. Parts of the flowering plant have been used in some cultures to treat certain medical problems. It may have anticancer effects. Also called Indian cress.

WBC
White blood cell. Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.

wedge resection
A surgical procedure to remove a triangle-shaped slice of tissue. It may be used to remove a tumor and a small amount of normal tissue around it.

Wermer's syndrome
A rare, inherited disorder that affects the endocrine glands and can cause tumors in the parathyroid and pituitary glands and the pancreas. These tumors (usually benign) cause the glands to secrete high levels of hormones, which can lead to other medical problems, such as kidney stones, fertility problems, and severe ulcers. In some cases, tumors inside the pancreas can become cancerous. Also called multiple endocrine adenomatosis and multiple endocrine neoplasia type 1 syndrome.

Whipple procedure
A type of surgery used to treat pancreatic cancer. The head of the pancreas, the duodenum, a portion of the stomach, and other nearby tissues are removed.

white blood cell
WBC. Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.

Whitmore-Jewett staging system
A staging system for prostate cancer that uses ABCD. “A” and “B” refer to cancer that is confined to the prostate. “C” refers to cancer that has grown out of the prostate but has not spread to lymph nodes or other places in the body. “D” refers to cancer that has spread to lymph nodes or to other places in the body. Also called the ABCD rating or the Jewett staging system.

whole cell vaccine
Vaccine made from whole tumor cells that have been changed in the laboratory.

wild clover
Trifolium pratense. A plant whose flowers have been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called red clover and purple clover.

Wilms' tumor
A kidney cancer that usually occurs in children younger than 5 years old.

windpipe
The airway that leads from the larynx to the lungs. Also called the trachea.

Wobe-Mugos E
A mixture made from an extract of the calf thymus gland and enzymes (proteins that speed up chemical reactions in the body) from the papaya plant, the pancreas of cows, and the pancreas of pigs. It has been used in Europe as a treatment for a variety of cancers and for herpes virus infections.

womb
The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a fetus develops. Also called the uterus.

X

x-ray
A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.

x-ray therapy
The use of high-energy radiation from x-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or from materials called radioisotopes. Radioisotopes produce radiation and can be placed in or near the tumor or in the area near cancer cells. This type of radiation treatment is called internal radiation therapy, implant radiation, interstitial radiation, or brachytherapy. Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. X-ray therapy is also called radiation therapy, radiotherapy, and irradiation.

xenograft
The cells of one species transplanted to another species.

xeroderma pigmentosum
A genetic condition characterized by a sensitivity to all sources of ultraviolet radiation.

xerogram
A picture of the body recorded on paper rather than on film. Also called a xeroradiograph.

xeroradiograph
A picture of the body recorded on paper rather than on film. Also called a xerogram.

xeroradiography  (ZEE-ro-ray-dee-AH-gra-fee)
A type of x-ray in which a picture of the body is recorded on paper rather than on film.

xerostomia
Dry mouth. It occurs when the body is not able to make enough saliva.

XK469
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called topoisomerase II beta inhibitors.

XR9576
A substance that is being studied for its ability to overcome tumor-cell resistance to anticancer drugs. It belongs to the family of drugs called anthranilic acid derivatives. Also called tariquidar.

Y

YM598
A substance that is being studied as a treatment for advanced prostate cancer and for pain caused by prostate cancer that has spread to the bone. It belongs to the family of drugs called endothelin ETA receptor antagonists.

yttrium  (IH-tree-um)
A rare elemental metal. A radioactive form of yttrium is used in radiation therapy and some types of immunotherapy.

yttrium Y 90 ibritumomab tiuxetan
An anticancer drug that is a combination of a monoclonal antibody and a radioisotope (yttrium-90). Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells. Also called IDEC-Y2B8 monoclonal antibody.

yttrium Y 90 SMT 487
A substance that is being studied as a treatment for cancer. Also called yttrium Y 90-DOTA-tyr3-octreotide.

yttrium Y 90-DOTA-tyr3-octreotide
A substance that is being studied in the treatment of cancer. Also called yttrium Y 90 SMT 487.

Z

ZD 1839
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors. Also called gefitinib.

ZD0473
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called platinum analogs.

ZD6474
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called vascular endothelial growth factor-2 (VEGF-2) receptor antagonists.

ziconotide
A drug used in the treatment of chronic pain. Also called SNX 111.

zidovudine
A drug that inhibits the human immunodeficiency virus (HIV) that causes AIDS. Also called AZT. It belongs to the family of drugs called systemic antivirals.

zileuton
A substance that is used to prevent asthma symptoms and that is being studied in the prevention of lung cancer. It belongs to the family of drugs called leukotriene inhibitors.

zinc oxide
A compound that may enhance immune function, especially when administered by inhalation.

zinc sulfate
A substance required for cell growth and tissue repair. It is being studied as a way to prevent or decrease mucositis caused by radiation therapy.

zoledronate
A drug that belongs to the family of drugs called bisphosphonates. It is used to prevent bone fractures and reduce bone pain in people who have cancer that has spread to the bone.

Zollinger-Ellison syndrome
A disorder in which tumors of the pancreatic islet cells produce large amounts of gastrin (a hormone), leading to excess acid in the stomach and, possibly, a peptic ulcer (ulcer of the stomach or the upper part of the small intestine).

Zoloft®
A drug that is used to treat depression. It belongs to the family of drugs called selective serotonin reuptake inhibitors (SSRIs). Also called sertraline.

zosuquidar trihydrochloride
A substance that is being studied for its ability to reverse resistance to chemotherapy. Also called LY335979.