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# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

D&C

Dilation and curettage. A minor operation in which the cervix is expanded enough (dilation) to permit the cervical canal and uterine lining to be scraped with a spoon-shaped instrument called a curette (curettage). Also called dilatation and curettage.

D-20761

A synthetic luteinizing hormone-releasing hormone (LH-RH) antagonist that suppresses LH and sex steroid levels.

DACA

Acridine carboxamide. A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called topoisomerase inhibitors.

dacarbazine

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

dacliximab

A monoclonal antibody that is being studied in the treatment of adult T-cell leukemia and in the treatment of cytopenia (low blood cell count). Also called daclizumab.

daclizumab

A monoclonal antibody that is being studied in the treatment of adult T-cell leukemia and in the treatment of cytopenia (low blood cell count). Also called dacliximab.

dactinomycin

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

da-huang

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, Chinese rhubarb, Indian rhubarb, and Turkish rhubarb.

daidzein

An isoflavone found in soy products. Soy isoflavones are being studied in the prevention of cancer.

dalteparin

A drug that helps prevent the formation of blood clots; it belongs to the family of drugs called anticoagulants.

danazol

A synthetic hormone that belongs to the family of drugs called androgens and is used to treat endometriosis. It is being evaluated in the treatment of endometrial cancer.

darbepoetin alfa (dar-be-POE-e-tin AL-fa)

A substance made in the laboratory that stimulates the bone marrow to produce red blood cells. It belongs to the family of drugs called antianemics.

dark-field microscope

A microscope (device used to magnify small objects) in which objects are lit at a very low angle from the side so that the background appears dark and the objects show up against this dark background.

Data Safety and Monitoring Committee

An impartial group that oversees a clinical trial and reviews the results to see if they are acceptable. This group determines if the trial should be changed or closed.

daunorubicin

An anticancer drug that belongs to the family of drugs called antitumor antibiotics. It is an anthracycline.

DCIS

Ductal carcinoma in situ. A noninvasive, precancerous condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. Also called intraductal carcinoma.

DDS

Denys-Drash syndrome. A rare disorder that causes kidney failure before age 3, abnormal development of the sexual organs, and, in most cases, Wilms' tumor (a type of kidney cancer). Children with Denys-Drash syndrome are also at high risk of some other types of cancer.

de novo (dih NO-vo)

In cancer, the first occurrence of cancer in the body.

death cap

Amanita phalloides. A type of poisonous mushroom that has harmful effects on the kidneys and liver. It is responsible for most fatal cases of mushroom poisoning.

decitabine

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

decortication (de-KOR-tih-KAY-shun)

Removal of part or all of the external surface of an organ.

deferoxamine

An iron-chelating agent that removes iron from tumors by inhibiting DNA synthesis and causing cancer cell death. It is used in conjunction with other anticancer agents in pediatric neuroblastoma therapy.

defibrotide

A substance that is being studied in the prevention of veno-occlusive disease, a rare complication of high-dose chemotherapy and stem cell transplantation in which small veins in the liver become blocked.

deficiency

In medicine, a shortage of a substance (such as a vitamin or mineral) needed by the body.

degenerative disease

A disease in which the function or structure of the affected tissues or organs changes for the worse over time. Osteoarthritis, osteoporosis, and Alzheimer's disease are examples.

dehydration

A condition caused by the loss of too much water from the body. Severe diarrhea or vomiting can cause dehydration.

dehydroepiandrosterone

DHEA. A substance that is being studied in the prevention of cancer. It belongs to the family of drugs called steroids.

delayed-type hypersensitivity response

DTH. An inflammatory response that develops 24 to 72 hours after exposure to an antigen that the immune system recognizes as foreign. This type of immune response involves mainly T cells rather than antibodies (which are made by B cells).

dendritic cell

A special type of antigen-presenting cell (APC) that activates T lymphocytes.

dendritic cell vaccine

A vaccine made of antigens and dendritic antigen-presenting cells (APCs).

denileukin diftitox (DEN-i-loo-kin DIF-ti-toks)

A substance used to treat cutaneous T-cell lymphoma when other treatments have not worked. It is also being studied in the treatment of chronic lymphocytic leukemia that has not responded to treatment. It belongs to the family of drugs called biological therapy agents.

dental implant

A metal, root-shaped device that is placed surgically in the jawbone. It acts as an anchor for attaching false teeth (crowns or bridges).

dentist

A health professional who specializes in caring for the teeth, gums, and other tissues in the mouth.

Denys-Drash syndrome

DDS. A rare disorder that causes kidney failure before age 3, abnormal development of the sexual organs, and, in most cases, Wilms' tumor (a type of kidney cancer). Children with Denys-Drash syndrome are also at high risk of some other types of cancer.

deoxycytidine

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

deoxyribonucleic acid

DNA. The molecules inside cells that carry genetic information and pass it from one generation to the next.

DepoFoam-encapsulated cytarabine

The anticancer drug cytarabine formulated inside small particles of a synthetic lipid material called DepoFoam. This dosage form slowly releases the drug and provides a sustained action.

depression (dee-PREH-shun)

A mental condition marked by ongoing feelings of sadness, despair, loss of energy, and difficulty dealing with normal daily life. Other symptoms of depression include feelings of worthlessness and hopelessness, loss of pleasure in activities, changes in eating or sleeping habits, and thoughts of death or suicide. Depression can affect anyone, and can be successfully treated. Depression affects 15-25% of cancer patients.

depsipeptide

A substance that is made naturally by some bacteria, fungi, and other organisms, and can also be made in the laboratory. Depsipeptides are being studied in the treatment of cancer.

derivative

In chemistry, a compound produced from or related to another.

dermatitis

Inflammation of the skin.

dermatofibrosarcoma protuberans (DER-ma-toe-FI-bro-sar-KO-ma pro-TOO-ber-anz)

A type of tumor that begins as a hard nodule and grows slowly. These tumors are usually found in the dermis (the inner layer of the two main layers of tissue that make up the skin) of the limbs or trunk of the body. They can grow into surrounding tissue but do not spread to other parts of the body. These tumors are related to giant cell fibroblastoma.

dermatologist (der-ma-TAH-loh-jist)

A doctor who has special training to diagnose and treat skin problems.

dermis (DER-mis)

The lower or inner layer of the two main layers of tissue that make up the skin.

DES

Diethylstilbestrol (dye-ETH-ul-stil-BES-trol). A synthetic form of the hormone estrogen that was prescribed to pregnant women between about 1940 and 1971 because it was thought to prevent miscarriages. DES may increase the risk of uterine, ovarian, or breast cancer in women who took it. DES also has been linked to an increased risk of clear cell carcinoma of the vagina or cervix in daughters exposed to DES before birth.

deslorelin

A substance that is being studied in the treatment of cancer as a way to block sex hormones made by the ovaries or testicles. It belongs to the family of drugs called gonadotropin-releasing hormone analogs.

desmoid tumor

A tumor of the tissue that surrounds muscles, usually in the abdomen. A desmoid tumor rarely metastasizes (spreads to other parts of the body). Also called aggressive fibromatosis, especially when the tumor is outside the abdomen.

desmoplastic

Causing or forming adhesions or fibrous connective tissue within a tumor.

desmoplastic melanoma

A rare form of malignant melanoma marked by nonpigmented lesions on sun-exposed areas of the body, most commonly on the head and neck.

desmoplastic small round cell tumor (dez-mo-PLAS-tik...)

A rare, aggressive cancer that usually affects young males and usually is located in the abdomen.

dexamethasone

A synthetic steroid (similar to steroid hormones produced naturally in the adrenal gland). Dexamethasone is used to treat leukemia and lymphoma and may be used to treat some of the problems caused by other cancers and their treatment.

dexmethylphenidate

A substance that is being studied in the treatment of fatigue and nervous system side effects caused by chemotherapy. It belongs to the family of drugs called central nervous system stimulants.

dexrazoxane

A drug used to protect the heart from the toxic effects of anthracycline drugs such as doxorubicin. It belongs to the family of drugs called chemoprotective agents.

dextroamphetamine-amphetamine

A combination of drugs that is used as a treatment for attention deficit hyperactivity disorder (ADHD) and narcolepsy (a sleep disorder). It belongs to the family of drugs called stimulants. Also called Adderall.

dextromethorphan acetic acid

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

DFMO

Difluoromethylornithine. A substance that is being studied in the treatment of cancer.

DHA-paclitaxel

A combination of DHA (a natural fatty acid) and paclitaxel (an anticancer drug) that is being studied in the treatment of cancer.

DHEA

Dehydroepiandrosterone. A substance that is being studied in the prevention of cancer. It belongs to the family of drugs called steroids.

diabetes (dye-a-BEE-teez)

A disease in which the body does not properly control the amount of sugar in the blood. As a result, the level of sugar in the blood is too high. This disease occurs when the body does not produce enough insulin or does not use it properly.

diabetes mellitus (dye-a-BEE-teez MEL-ih-tus)

A group of disorders in which there is a defect in the transfer of glucose (sugar) from the bloodstream into cells, leading to abnormally high levels of blood sugar (hyperglycemia).

diagnosis

The process of identifying a disease by the signs and symptoms.

diagnostic mammogram

X-ray of the breasts used to check for breast cancer after a lump or other sign or symptom of breast cancer has been found.

diagnostic procedure

A method used to identify a disease.

diagnostic trial

A research study that evaluates methods of detecting disease.

dialysis (dye-AL-ih-sis)

The process of filtering the blood when the kidneys are not able to cleanse it.

diameter

The length of a straight line that extends from one edge of a tumor or other object, through its center and to the opposite edge. It is usually used to measure the size of round or spherical shapes.

diaphragm (DYE-a-fram)

The thin muscle below the lungs and heart that separates the chest from the abdomen.

diarrhea

Frequent and watery bowel movements.

diathermy (DYE-a-ther-mee)

The use of heat to destroy abnormal cells. Also called cauterization or electrodiathermy.

diaziquone

AZQ. An anticancer drug that is able to cross the blood-brain barrier and kill cancer cells in the central nervous system.

didanosine

A drug used in the treatment of infections caused by viruses.

di-dgA-RFB4

An anticancer drug that is a combination of a monoclonal antibody (RFB4) and an immunotoxin (dgA).

DIEP flap

A type of breast reconstruction in which blood vessels called deep inferior epigastric perforators (DIEP), and the skin and fat connected to them are removed from the lower abdomen and used for reconstruction. Muscle is left in place.

diet

The things a person eats and drinks.

dietary supplement

Vitamins, minerals, or other substances taken by mouth, and intended as an addition to the diet.

diethylstilbestrol (dye-ETH-ul-stil-BES-trol)

DES. A synthetic form of the hormone estrogen that was prescribed to pregnant women between about 1940 and 1971 because it was thought to prevent miscarriages. DES may increase the risk of uterine, ovarian, or breast cancer in women who took it. DES also has been linked to an increased risk of clear cell carcinoma of the vagina or cervix in daughters exposed to DES before birth.

dietitian (dy-eh-TIH-shun)

A health professional with special training in nutrition who can help with dietary choices. Also called a nutritionist.

differentiation

In cancer, refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and tend to grow and spread at a slower rate than undifferentiated or poorly differentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.

diffuse

Widely spread; not localized or confined.

diffuse large B-cell lymphoma (lim-FOH-muh)

A type of B-cell non-Hodgkin's lymphoma (cancer of the immune system) that is usually aggressive (fast-growing). It is the most common type of non-Hodgkin's lymphoma, and is marked by rapidly growing tumors in the lymph nodes, spleen, liver, bone marrow, or other organs. Other symptoms include fever, night sweats, and weight loss. There are several subtypes of diffuse large B-cell lymphoma.

difluoromethylornithine

DFMO. A substance that is being studied in the treatment of cancer.

digestive system (dye-JES-tiv)

The organs that take in food and turn it into products that the body can use to stay healthy. Waste products the body cannot use leave the body through bowel movements. The digestive system includes the salivary glands, mouth, esophagus, stomach, liver, pancreas, gallbladder, small and large intestines, and rectum.

digestive tract (dy-JES-tiv)

The organs through which food and liquids pass when they are swallowed, digested, and eliminated. These organs are the mouth, esophagus, stomach, small and large intestines, and rectum and anus.

digital mammography

A technique that uses a computer, rather than x-ray film, to record x-ray images of the breast.

digital photography

A type of photography in which images can be viewed on a computer screen.

digital rectal examination

DRE. An examination in which a doctor inserts a lubricated, gloved finger into the rectum to feel for abnormalities.

dihematoporphyrin ether

Used in photodynamic therapy, a drug that is absorbed by tumor cells; when exposed to light, it becomes active and kills the cancer cells.

dilatation and curettage (DIH-luh-TA-shun and KYUR-eh-TAHJ)

D&C. A procedure to remove tissue from the cervical canal or the inner lining of the uterus. The cervix is dilated (made larger) and a curette (spoon-shaped instrument) is inserted into the uterus to remove tissue. Also called dilation and curettage.

dilate (DYE-late)

To widen or enlarge an opening or hollow structure beyond its usual size, such as the pupil of the eye or a blood vessel.

dilation and curettage (DY-LAY-shun and KYUR-eh-TAHJ)

D&C. A procedure to remove tissue from the cervical canal or the inner lining of the uterus. The cervix is dilated (made larger) and a curette (spoon-shaped instrument) is inserted into the uterus to remove tissue. Also called dilatation and curettage.

dilator (DYE-lay-tor)

A device used to stretch or enlarge an opening.

dimesna

A drug that belongs to the family of drugs called chemoprotective agents.

dimethyl sulfoxide

A colorless liquid that readily dissolves many chemicals and penetrates animal and plant tissues. It is used in human medicine, veterinary medicine, and pharmaceuticals.

dimethylxanthenone acetic acid

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

diphosphonate

A drug used to treat osteoporosis and the bone pain caused by some types of cancer. Also called bisphosphonate.

dipyridamole

A drug that prevents blood cell clumping and enhances the effectiveness of fluorouracil and other chemotherapeutic agents.

disease progression

Cancer that continues to grow or spread.

disease-free survival

Length of time after treatment during which no cancer is found. Can be reported for an individual patient or for a study population.

disease-specific survival

The percentage of subjects in a study who have survived a particular disease for a defined period of time. Usually reported as time since diagnosis or treatment. In calculating this percentage, only deaths from the disease being studied are counted. Subjects who died from some other cause are not included in the calculation.

disorder (diss-ORE-der)

In medicine, a disturbance of normal functioning of the mind or body. Disorders may be caused by genetic factors, disease, or trauma.

disseminate (dih-SEM-ih-NATE)

Scatter or distribute over a large area or range.

distal

In medicine, refers to a part of the body that is farther away from the center of the body than another part. For example, the fingers are distal to the shoulder. The opposite is proximal.

distal pancreatectomy

Removal of the body and tail of the pancreas.

distant cancer

Refers to cancer that has spread from the original (primary) tumor to distant organs or distant lymph nodes. Also known as distant metastasis.

distant metastasis

Refers to cancer that has spread from the original (primary) tumor to distant organs or distant lymph nodes. Also known as distant cancer.

distraction

In medicine, a pain relief method that takes the patient's attention away from the pain.

disulfiram

A drug that slows the metabolism of retinoids, allowing them to act over a longer period of time.

diuretic

A drug that increases the production of urine.

diverticulosis

A condition marked by small sacs or pouches (diverticula) in the walls of an organ such as the stomach or colon. These sacs can become inflamed and cause a condition called diverticulitis, which may be a risk factor for certain types of cancer.

DJ-927

A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called taxane derivatives.

DNA

Deoxyribonucleic acid. The molecules inside cells that carry genetic information and pass it from one generation to the next.

DNR order

Do not resuscitate order. A type of advance directive in which a person states that healthcare providers should not perform cardiopulmonary resuscitation (restarting the heart) if his or her heart or breathing stops.

do not resuscitate order (.ree-SUH-sih-TAYT.)

DNR order. A type of advance directive in which a person states that healthcare providers should not perform cardiopulmonary resuscitation (restarting the heart) if his or her heart or breathing stops.

docetaxel

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

dock

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 sorrel.

dolasetron

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

dolastatin 10

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

donepezil

A drug used in the treatment of Alzheimer's disease. It belongs to the family of drugs called cholinesterase inhibitors. It is being studied in the treatment of side effects caused by radiation therapy to the brain.

dose

The amount of medicine taken, or radiation given, at one time.

dose-dense chemotherapy

A chemotherapy treatment plan in which drugs are given with less time between treatments than in a standard chemotherapy treatment plan.

dose-dependent

Refers to the effects of treatment with a drug. If the effects change when the dose of the drug is changed, the effects are said to be dose-dependent.

dose-limiting

Describes side effects of a drug or other treatment that are serious enough to prevent an increase in dose or level of that treatment.

dose-rate

The strength of a treatment given over a period of time.

dosimetrist do-SIM-uh-trist

A person who determines the proper radiation dose for treatment.

double-blinded

A clinical trial in which neither the medical staff nor the person knows which of several possible therapies the person is receiving.

double-contrast barium enema

A procedure in which x-rays of the colon and rectum are taken after a liquid containing barium is put into the rectum. Barium is a silver-white metallic compound that outlines the colon and rectum on an x-ray and helps show abnormalities. Air is put into the rectum and colon to further enhance the x-ray.

doubling time (DUH-bling...)

In biology, the amount of time it takes for one cell to divide or for a group of cells (such as a tumor) to double in size. The doubling time is different for different kinds of cancer cells or tumors.

douche (DOOSH)

A procedure in which water or a medicated solution is used to clean the vagina and cervix.

Down syndrome

A disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation and distinguishing physical features.

doxercalciferol

A substance that is being studied in the prevention of recurrent prostate cancer. It belongs to the family of drugs called vitamin D analogs.

doxorubicin

An anticancer drug that belongs to the family of drugs called antitumor antibiotics. It is an anthracycline. Also called Adriamycin.

doxycycline

An antibiotic drug used to treat infection.

DPA

Durable power of attorney. A document that gives a person (such as a relative, lawyer, or friend) the authority to make legal or financial decisions for another person. It may become active immediately, or when that person loses the ability to make decisions for himself or herself, depending on how it is written.

DPPE

Belongs to a group of antihormone drugs.

drain

In medicine, to remove fluid as it collects; or, a tube or wick-like device used to remove fluid from a body cavity, wound, or infected area.

DRE

Digital rectal examination. An examination in which a doctor inserts a lubricated, gloved finger into the rectum to feel for abnormalities.

dronabinol

A synthetic pill form of delta-9-tetrahydrocannabinol (THC), an active ingredient in marijuana that is used to treat nausea and vomiting associated with cancer chemotherapy.

drug

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

drug resistance

The failure of cancer cells, viruses, or bacteria to respond to a drug used to kill or weaken them. The cells, viruses, or bacteria may be resistant to the drug at the beginning of treatment, or may become resistant after being exposed to the drug.

drug tolerance

A condition that occurs when the body gets used to a medicine so that either more medicine is needed or different medicine is needed.

dry orgasm

Sexual climax without the release of semen from the penis.

DTGM fusion protein

An anticancer drug formed by the combination of diphtheria toxin and a colony-stimulating factor (GM-CSF). The colony-stimulating factor is attracted to cancer cells, and the diphtheria toxin kills the cells.

DU 145

A cell line made from human prostate cancer cells that is used in the laboratory to study the way prostate cancer cells grow.

duct (dukt)

In medicine, a tube or vessel of the body through which fluids pass.

ductal carcinoma

The most common type of breast cancer. It begins in the cells that line the milk ducts in the breast.

ductal carcinoma in situ (DUK-tal KAR-sih-NOH-muh in SYE-too)

DCIS. A noninvasive, precancerous condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, ductal carcinoma in situ may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. Also called intraductal carcinoma.

ductal lavage (DUK-tal luh-VAHZ)

A method used to collect cells from milk ducts in the breast. A hair-size catheter (tube) is inserted into the nipple, and a small amount of salt water is released into the duct. The water picks up breast cells, and is removed. The cells are checked under a microscope. Ductal lavage may be used in addition to clinical breast examination and mammography to detect breast cancer.

Dukes' classification

A staging system used to describe the extent of colorectal cancer. Stages range from A (early stage) to D (advanced stage).

dumping syndrome

A condition that occurs when food or liquid moves too fast into the small intestine. Symptoms include cramps, nausea, diarrhea, sweating, weakness, and dizziness. Dumping syndrome sometimes occurs in people who have had part or all of their stomach removed.

duodenitis

Inflammation of the duodenum (the first part of the small intestine that connects to the stomach).

duodenum (doo-ah-DEE-num)

The first part of the small intestine that connects to the stomach.

durable power of attorney (DUR-uh-bul.uh-TUR-nee)

DPA. A document that gives a person (such as a relative, lawyer, or friend) the authority to make legal or financial decisions for another person. It may become active immediately, or when that person loses the ability to make decisions for himself or herself, depending on how it is written.

DX-52-1

An anticancer drug that belongs to the family of drugs called antitumor antibiotics. It is an anthracycline.

DX-8951f

An anticancer drug that belongs to the family of drugs called topoisomerase inhibitors. Also called exatecan mesylate.

dyscrasia

Disease. Usually refers to diseases of the blood.

dysesthesia

A condition in which a sense, especially touch, is distorted. Dysesthesia can cause an ordinary stimulus to be unpleasant or painful. It can also cause insensitivity to a stimulus.

dysfunction

A state of not functioning normally.

dysgeusia

A bad taste in the mouth. Also called parageusia.

dyspepsia

Upset stomach.

dysphagia

Difficulty swallowing.

dysplasia (dis-PLAY-zha)

Cells that look abnormal under a microscope but are not cancer.

dysplastic nevi (dis-PLAS-tik NEE-vye)

Atypical moles; moles whose appearance is different from that of common moles. Dysplastic nevi are generally larger than ordinary moles and have irregular and indistinct borders. Their color frequently is not uniform and ranges from pink to dark brown; they usually are flat, but parts may be raised above the skin surface.

dysplastic nevus (dis-PLAS-tik NEE-vus)

An atypical mole; a mole whose appearance is different from that of a common mole. A dysplastic nevus is generally larger than an ordinary mole and has irregular and indistinct borders. Its color frequently is not uniform and ranges from pink to dark brown; it is usually flat, but parts may be raised above the skin surface.

dyspnea

Difficult, painful breathing or shortness of breath.