fallopian tubes (fa-LO-pee-in): Part of the female reproductive tract. The long slender tubes through which eggs pass from the ovaries to the uterus.

familial dysplastic nevi (fa-MI-lee-yul dis-PLAS-tik NEE-vye): A condition that runs in certain families in which at least two members have dysplastic nevi (atypical moles) and have a tendency to develop melanoma.

familial polyposis (pah-li-PO-sis): An inherited condition in which numerous polyps (tissue masses) develop on the inside walls of the colon and rectum. It increases the risk for colon cancer.

Fanconi anemia: A rare and often fatal inherited disease in which the bone marrow fails to produce red blood cells, white blood cells, platelets, or a combination of these cells. The disease may transform into myelodysplastic syndrome or leukemia. Also called Fanconi's syndrome.

Fanconi's syndrome: A rare and often fatal inherited disease in which the bone marrow fails to produce red blood cells, white blood cells, platelets, or a combination of these cells. The disease may transform into myelodysplastic syndrome or leukemia. Also called Fanconi anemia.

fatty acids: A major component of fats that are used by the body for energy and tissue development.

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

fecal occult blood test (FEE-kul o-KULT): A test to check for blood in stool. (Fecal refers to stool; occult means hidden.)

fenretinide: A drug being studied for cancer prevention; it belongs to the family of drugs called retinoids.

fentanyl: A narcotic opioid drug that is used in the treatment of pain.

fertility (fer-TIL-i-tee): The ability to produce children.

fetus (FEET-us): The developing offspring from 7 to 8 weeks after conception until birth.

fiber: The parts of fruits and vegetables that cannot be digested. Also called bulk or roughage. Fiber may be effective in preventing cancer.

fibroid (FYE-broyd): A benign smooth muscle tumor, usually in the uterus or gastrointestinal tract. Also called leiomyoma.

fibrosarcoma: A type of soft tissue sarcoma that begins in fibrous tissue, which holds bones, muscles, and other organs in place.

fibrosis: The growth of fibrous tissue.

filgrastim: A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called granulocyte colony-stimulating factor (G-CSF).

filgrastim-SD/01: 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.

filler: An inactive substance used to make a product bigger or easier to handle. For example, fillers are often used to make pills or capsules because the amount of active drug is too small to be handled conveniently.

finasteride: A drug used to reduce the amount of male hormone (testosterone) produced by the body.

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

FK463: An antibiotic/antifungal drug used to treat infection.

flavopiridol: Belongs to the family of anticancer drugs called flavinols.

flecainide: A drug that is used to treat abnormal heart rhythms. It may also relieve neuropathic pain, the burning, stabbing, or stinging pain that may arise from damage to nerves caused by some types of cancer or cancer treatment.

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

flt3L: A drug that increases the number of immune cells and may stimulate the immune system to kill cancer cells.

fluconazole: A drug that treats infections caused by fungi.

flucytosine: A drug that treats infections caused by fungi.

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

fludeoxyglucose F 18: The radioactive form of glucose used in positron emission tomography (PET), a diagnostic imaging procedure.

fludrocortisone: A synthetic corticosteroid. It is used to replace steroid hormones normally produced by the adrenal gland.

fluoroscope (FLOOR-o-skope): An x-ray machine that makes it possible to see internal organs in motion.

fluoroscopy (floor-AHS-ko-pee): An x-ray procedure that makes it possible to see internal organs in motion.

fluorouracil (floor-o-YOOR-a-sil): An anticancer drug that belongs to the family of drugs called antimetabolites.

fluoxetine: A drug used to treat depression. It belongs to the family of drugs called antidepressants.

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

folate: A B-complex vitamin that is being studied as a cancer prevention agent. Also called folic acid.

folic acid: A B-complex vitamin that is being studied as a cancer prevention agent. Also called folate.

follicles (FOL-i-kuls): Shafts through which hair grows.

follicular large cell lymphoma (foll-IK-yew-lar large cell lim- FO-ma): A rare type of non- Hodgkin's lymphoma (cancer of the lymphatic system) with large cells that look cleaved (split) or non-cleaved under the microscope. It is an indolent (slow-growing) type of lymphoma.

FR901228: An anticancer drug that belongs to the family of drugs called depsipeptides.

fractionation: Dividing the total dose of radiation therapy into several smaller, equal doses delivered over a period of several days.

free radicals: Highly reactive chemicals that often contain oxygen and are produced when molecules are split to give products that have unpaired electrons. This process is called oxidation. Free radicals can damage important cellular molecules such as DNA or lipids or other parts of the cell.

freeze-dried: A method used to dry substances, such as food, to make them last longer. The substance is frozen and then dried in a vacuum.

fulguration (ful-gyoor-AY-shun): Destroying tissue using an electric current.

functional magnetic resonance imaging: A noninvasive tool used to observe functioning in the brain or other organs by detecting changes in chemical composition, blood flow, or both.

fundus: The larger part of a hollow organ that is farthest away from the organ's opening. The bladder, gallbladder, stomach, uterus, eye, and cavity of the middle ear all have a fundus.