B cells: White blood cells that develop from bone marrow and produce antibodies. Also called B lymphocytes.

B lymphocytes: White blood cells that make antibodies and are an important part of the immune system. B lymphocytes come from bone marrow. Also called B cells.

B3 antigen: A protein found on some tumor cells.

B43-BAP immunotoxin: A toxic substance linked to an antibody that attaches to tumor cells and kills them.

bacteria: A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.

bacterial toxin: A toxic substance, made by bacteria, that can be modified to kill specific tumor cells without harming normal cells.

barbiturate: A drug with sedative and hypnotic effects. Barbiturates have been used as sedatives and anesthetics, and they have been used to treat the convulsions associated with epilepsy.

barium enema: A procedure in which a liquid with barium in it is put into the rectum and colon by way of the anus. Barium is a silver-white metallic compound that helps to show the image of the lower gastrointestinal tract on an x-ray.

barium solution: A liquid containing barium sulfate that is used in x-rays to highlight parts of the digestive system.

barium swallow: A series of x-rays of the esophagus. The x-ray pictures are taken after the person drinks a solution that contains barium. The barium coats and outlines the esophagus on the x-ray. Also called an esophagram.

Barrett's esophagus: A condition in which the cells lining the lower part of the esophagus have changed or been replaced with abnormal cells that could lead to cancer of the esophagus. The backing up of stomach contents (reflux) may irritate the esophagus and, over time, cause Barrett's esophagus.

basal cell carcinoma (BAY-sal sel kar-sin-O-ma): A type of skin cancer that arises from the basal cells, small round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.

basal cells (BAY-sal): Small, round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.

basophil: A type of white blood cell. Basophils are granulocytes.

batimastat: An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Batimastat is a matrix metalloproteinase inhibitor.

BAY 12-9566: An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors.

BBR 3464: A substance that is being studied as an anticancer drug. It belongs to the family of platinum-based drugs.

BCG vaccine: An anticancer drug (bacille calmette-Guerin) that activates the immune system. Filling the bladder with a solution of BCG is a form of biological therapy for superficial bladder cancer.

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

beclomethasone: A drug being studied in the treatment of graft-versus-host disease. It belongs to a family of drugs called corticosteroids.

benign (beh-NINE): Not cancerous; does not invade nearby tissue or spread to other parts of the body.

benign prostatic hyperplasia (hye-per-PLAY-zha): A benign (noncancerous) condition in which an overgrowth of prostate tissue pushes against the urethra and the bladder, blocking the flow of urine. Also called benign prostatic hypertrophy or BPH.

benign tumor (beh-NINE): A noncancerous growth that does not invade nearby tissue or spread to other parts of the body.

benzaldehyde: A colorless oily liquid used as a flavoring agent and to make dyes, perfumes, and pharmaceuticals. Benzaldehyde is chemically related to benzene.

benzoylphenylurea: A substance that is being studied as an anticancer drug. It belongs to the family of drugs called antitubulin agents. Also called BPU.

Beriplast P: A substance used in surgical wound healing to cause a blood clot to form. It consists of blood-clotting factors found naturally in human blood.

beta alethine: A substance that is being studied as a treatment for cancer. It belongs to a family of chemicals called disulfides.

beta carotene: A vitamin A precursor. Beta carotene belongs to the family of fat-soluble vitamins called carotenoids.

beta hemolytic streptococcus group B: A type of bacteria often found in the vagina. It can cause systemic infections in people with suppressed immune systems.

beta-endorphin: A neuropeptide that mediates pain perception.

beta-glucans: Polysaccharides made by several types of mushrooms. Beta-glucans have been used to treat patients with gastric cancer and colorectal cancer. They may be able to stimulate the immune system.

bevacizumab: A monoclonal antibody that may prevent the growth of blood vessels from surrounding tissue to a solid tumor.

bexarotene: An anticancer drug used to decrease the growth of some types of cancer cells. Also called LGD1069.

Biafine cream: A topical preparation to reduce the risk of, and treat skin reactions to, radiation therapy.

BIBX 1382: A drug that may inhibit tumor cells from multiplying. It is being studied for its ability to treat cancer.

bicalutamide: An anticancer drug that belongs to the family of drugs called antiandrogens.

bilateral: Affecting both the right and left side of body.

bilateral cancer: Cancer that occurs in both paired organs, such as both breasts or both ovaries.

bile: A fluid made by the liver and stored in the gallbladder. Bile is excreted into the small intestine where it helps digest fat.

bile duct: A tube through which bile passes in and out of the liver.

biliary: Having to do with the liver, bile ducts, and/or gallbladder.

binding agent: A substance that makes a loose mixture stick together. For example, binding agents can be used to make solid pills from loose powders.

bioavailable: The ability of a drug or other substance to be absorbed and used by the body. Orally bioavailable means that a drug or other substance that is taken by mouth can be absorbed and used by the body.

biochanin A: An isoflavone found in soy products. Soy isoflavones are being studied to see if they help prevent cancer.

biochemical reactions: In living cells, chemical reactions that help sustain life and allow cells to grow.

biological response modifier (by-o-LAHJ-i-kul): BRM. A substance that stimulates the body's response to infection and disease.

biological therapy (by-o-LAHJ-i-kul): Treatment to stimulate or restore the ability of the immune system to fight infection and disease. Also used to lessen side effects that may be caused by some cancer treatments. Also known as immunotherapy, biotherapy, or biological response modifier (BRM) therapy.

biomarkers: Substances sometimes found in an increased amount in the blood, other body fluids, or tissues and that may suggest the presence of some types of cancer. Biomarkers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and GI tract cancers), and PSA (prostate cancer). Also called tumor markers.

Biomed 101: A substance that is being studied for its ability to decrease the side effects of interleukin-2 (IL-2).

biopsy (BY-ahp-see): The removal of cells or tissues for examination under a microscope. When only a sample of tissue is removed, the procedure is called an incisional biopsy or core biopsy. When an entire tumor or lesion is removed, the procedure is called an excisional biopsy. When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy or fine-needle htmliration.

biopsy specimen: Tissue removed from the body and examined under a microscope to determine whether disease is present.

bispecific antibodies: Antibodies developed in the laboratory to recognize more than one protein on the surface of different cells. Examples include bispecific antibodies 2B1, 520C9xH22, mDX-H210, and MDX447.

bizelesin: An anticancer drug that belongs to the family of drugs called alkylating agents. It is also an antitumor antibiotic.

BL22 immunotoxin: An anticancer drug that belongs to the family of drugs called bacterial immunotoxins. BL22 is a bacterial toxic substance linked to an antibody that attaches to tumor cells and kills them.

bladder: The organ that stores urine.

blast crisis: The phase of chronic myelogenous leukemia in which the number of immature, abnormal white blood cells in the bone marrow and blood is extremely high. Also called blast phase.

blast phase: The phase of chronic myelogenous leukemia in which the number of immature, abnormal white blood cells in the bone marrow and blood is extremely high. Also called blast crisis.

blasts: Immature blood cells.

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

blood transfusion: The administration of blood or blood products into a blood vessel.

blood vessel: A tube in the body through which blood circulates. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

blood-brain barrier: A network of blood vessels with closely spaced cells that makes it difficult for potentially toxic substances (such as anticancer drugs) to penetrate the blood vessel walls and enter the brain.

BMS-182751: A platinum compound used in chemotherapy.

BMS-184476: An anticancer drug that belongs to the family of drugs called mitotic inhibitors.

BMS-188797: A substance that is being studied as a treatment for cancer.

BMS-214662: A substance that is being studied as a treatment for cancer.

BMS-247550: A substance that is being studied as a treatment for cancer.

BMS-275291: A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called matrix metalloproteinase inhibitors (MMPI).

bolus: A single dose of drug usually injected into a blood vessel over a short period of time. Also called bolus infusion.

bolus infusion: A single dose of drug usually injected into a blood vessel over a short period of time. Also called bolus.

bone marrow: The soft, sponge-like tissue in the center of bones that produces white blood cells, red blood cells, and platelets.

bone marrow ablation: The destruction of bone marrow using radiation or drugs.

bone marrow htmliration (as-per-AY-shun): The removal of a small sample of bone marrow (usually from the hip) through a needle for examination under a microscope.

bone marrow biopsy (BY-ahp-see): The removal of a sample of tissue from the bone marrow with a needle for examination under a microscope.

bone marrow metastases: Cancer that has spread from the original (primary) tumor to the bone marrow.

bone marrow transplantation (trans-plan-TAY-shun): A procedure to replace bone marrow destroyed by treatment with high doses of anticancer drugs or radiation. Transplantation may be autologous (an individual's own marrow saved before treatment), allogeneic (marrow donated by someone else), or syngeneic (marrow donated by an identical twin).

bone metastases: Cancer that has spread from the original (primary) tumor to the bone.

bone scan: A technique to create images of bones on a computer screen or on film. A small amount of radioactive material is injected into a blood vessel and travels through the bloodstream; it collects in the bones and is detected by a scanner.

boron neutron capture therapy: A type of radiation therapy. The person is given an intravenous infusion containing the element boron, which concentrates in the tumor cells. The person then receives radiation therapy with atomic particles called neutrons from a small research nuclear reactor. The radiation is absorbed by the boron, killing the tumor cells without harming normal cells.

bowel: The long tube-shaped organ in the abdomen that completes the process of digestion. There is both a small and a large bowel. Also called the intestine.

Bowen's disease (BO-uns disease): 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 sun- exposed areas of the skin and in older, white men. These patches may become malignant (cancerous). Also called precancerous dermatosis or precancerous dermatitis.

brachytherapy (BRAKE-ih-THER-a-pee): A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called internal radiation, implant radiation, or interstitial radiation therapy.

brain metastases: Cancer that has spread from the original (primary) tumor to the brain.

brain stem: The part of the brain that is connected to the spinal cord.

brain stem glioma (glee-O-ma): A tumor located in the part of the brain that connects to the spinal cord (the brain stem). It may grow rapidly or slowly, depending on the grade of the tumor.

brain stem tumor: A tumor in the part of the brain that connects to the spinal cord (the brain stem).

BRCA1: A gene located on chromosome 17 that normally helps to suppress cell growth. Inheriting an altered version of BRCA1 predisposes an individual to breast, ovarian, or prostate cancer.

BRCA2: A gene on chromosome 13 that normally helps to suppress cell growth. A person who inherits an altered version of the BRCA2 gene has a higher risk of getting breast, ovarian, or prostate cancer.

breast reconstruction: Surgery to rebuild a breast's shape after a mastectomy.

breast-conserving surgery: An operation to remove the breast cancer but not the breast itself. Types of breast-conserving surgery include lumpectomy (removal of the lump), quadrantectomy (removal of one quarter of the breast), and segmental mastectomy (removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor).

Brief Pain Inventory: A questionnaire used to measure pain.

bromelain: An enzyme found in pineapples that breaks down other proteins, such as collagen and muscle fiber, and has anti-inflammatory properties. It is used as a meat tenderizer in the food industry.

bronchi (BRONK-eye): The large air passages that lead from the trachea (windpipe) to the lungs.

bronchioles (BRON-kee-olz): The tiny branches of air tubes in the lungs.

bronchitis (bron-KYE-tis): Inflammation (swelling and reddening) of the bronchi.

bronchoscope (BRON-ko-skope): A thin, lighted tube used to examine the inside of the trachea and bronchi, the air passages that lead into the lungs.

bronchoscopy (bron-KOS-ko-pee): A procedure in which a thin, lighted tube is inserted through the nose or mouth. This allows examination of the inside of the trachea and bronchi (air passages that lead to the lung), as well as the lung. Bronchoscopy may be used to detect cancer or to perform some treatment procedures.

bronchus: A large air passage that leads from the trachea (windpipe) to the lung.

broxuridine: A drug that makes cancer cells more sensitive to radiation and is also used as a diagnostic agent to determine how fast cancer cells grow.

bryostatin-1: A drug used for its antitumor activity.

buccal mucosa (BUK-ul myoo-KO-sa): The inner lining of the cheeks and lips.

budesonide: A steroid being studied as an anticancer drug. Budesonide is commonly used to treat asthma and rhinitis.

Burkitt's lymphoma: A type of non-Hodgkin's lymphoma that most often occurs in young people aged 12-30 years. The disease usually causes a rapidly growing tumor in the abdomen.

buserelin: An anticancer drug that belongs to the family of drugs called gonadotropin-releasing hormones. In prostate cancer therapy, buserelin blocks the production of testosterone in the testicles.

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

buthionine sulfoximine: A drug that may help prevent resistance to some anticancer drugs.

bypass: A surgical procedure in which the doctor creates a new pathway for the flow of body fluids.