National Cancer Institute
U.S. National Institutes of Health | www.cancer.gov

NCI Home
Cancer Topics
Clinical Trials
Cancer Statistics
Research & Funding
News
About NCI
Dictionary of Cancer Terms
In English   En español
Page Options
Print This Page
Quick Links
Director's Corner
Updates from the Director

Dictionary of Cancer Terms
Cancer-related terms

NCI Drug Dictionary
Definitions, names, and links

Funding Opportunities
Research and training

NCI Publications
Order/download free booklets

Advisory Boards and Groups
Information, meetings, reports

Science Serving People
Learn more about NCI

Español
Información en español
NCI Highlights
NCI Responds to Hurricanes

The Cancer Genome Atlas Reports Brain Tumors Study

The Nation's Investment in Cancer Research FY 2009

Cancer Trends Progress Report: 2007 Update

Past Highlights
You CAN Quit Smoking Now!
Search for
# 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

145 results found for:   
  F



falimarev  (fuh-LIM-uh-rev)
A cancer vaccine made with a form of a chicken virus that does not cause disease in humans. It is being studied in the treatment of some types of cancer. The virus is changed in the laboratory to make human proteins that may help immune cells in the body kill tumor cells. Also called recombinant fowlpox-CEA-MUC-1-TRICOM vaccine.

fallopian tube  (fuh-LOH-pee-in...)
A slender tube through which eggs pass from an ovary to the uterus. In the female reproductive tract, there is one ovary and one fallopian tube on each side of the uterus.

false-negative test result  
A test result that indicates that a person does not have a specific disease or condition when the person actually does have the disease or condition.

false-positive test result  (fawls-PAH-zih-tiv ... reh-ZULT)
A test result that indicates that a person has a specific disease or condition when the person actually does not have the disease or condition.

familial adenomatous polyposis  (fuh-MIH-lee-ul A-deh-NOH-muh-tus PAH-lee-POH-sis)
An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called FAP and familial polyposis.

familial atypical multiple mole melanoma syndrome  
FAMMM syndrome. An inherited condition marked by the following: (1) one or more first- or second-degree relatives (parent, sibling, child, grandparent, grandchild, aunt, or uncle) with malignant melanoma; (2) many moles, some of which are atypical (asymmetrical, raised, and/or different shades of tan, brown, black, or red) and often of different sizes; and (3) moles that have specific features when examined under a microscope. FAMMM syndrome increases the risk of melanoma and may increase the risk of pancreatic cancer. Also called FAMMM syndrome.

familial cancer  
Cancer that occurs in families more often than would be expected by chance. These cancers often occur at an early age, and may indicate the presence of a gene mutation that increases the risk of cancer. They may also be a sign of shared environmental or lifestyle factors.

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 isolated hyperparathyroidism  (fuh-MIH-lee-ul I-soh-LAY-ted HY-per-PAYR-uh-THY-roy-dih-zum)
FIHP. A rare inherited condition in which one or more tumors form in the parathyroid glands (four pea-sized organs found on the thyroid) and cause them to make too much parathyroid hormone. The increased parathyroid hormone causes a loss of calcium from the bones and too much calcium in the blood. Also called FIHP.

familial medullary thyroid cancer  (fuh-MIH-lee-ul MED-yoo-LAYR-ee THY-royd KAN-ser)
An inherited form of medullary thyroid cancer (cancer that forms in the cells of the thyroid that make the hormone calcitonin).

familial polyposis  (fuh-MIH-lee-ul PAH-lee-POH-sis)
An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called familial adenomatous polyposis and FAP.

family history  
A record of a person's current and past illnesses, and those of his or her parents, brothers, sisters, children, and other family members. A family history shows the pattern of certain diseases in a family, and helps to determine risk factors for those and other diseases.

family therapy  (FAM-ih-lee THAYR-uh-pee)
A type of therapy in which the whole family talks with a professional counselor to solve family problems.

FAMMM syndrome  
Familial atypical multiple mole melanoma syndrome. An inherited condition marked by the following: (1) one or more first- or second-degree relatives (parent, sibling, child, grandparent, grandchild, aunt, or uncle) with malignant melanoma; (2) many moles, some of which are atypical (asymmetrical, raised, and/or different shades of tan, brown, black, or red) and often of different sizes; and (3) moles that have specific features when examined under a microscope. FAMMM syndrome increases the risk of melanoma and may increase the risk of pancreatic cancer. Also called familial atypical multiple mole melanoma syndrome.

Fanconi anemia  (fan-KOH-nee uh-NEE-mee-uh)
A rare inherited disorder in which the bone marrow does not make blood cells. It is usually diagnosed in children between 2 and 15 years old. Symptoms include frequent infections, easy bleeding, and extreme tiredness. People with Fanconi anemia may have a small skeleton and brown spots on the skin. They also have an increased risk of developing certain types of cancer.

Fanconi syndrome  (fan-KOH-nee SIN-drome)
A group of kidney disorders that cause protein, sugar, minerals, and other nutrients to be lost in the urine. Symptoms include weakness, bone pain, and passing a greater than normal amount of urine. One form of Fanconi syndrome is inherited and is usually found in infants. Fanconi’s syndrome may also be caused by other diseases, a lack of vitamin D, or exposure to heavy metals or chemicals, including certain anticancer drugs.

FAP  
An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called familial adenomatous polyposis and familial polyposis.

Faslodex  (FAZ-loh-dex)
A drug used to treat certain types of breast cancer in postmenopausal women. It is also being studied in the treatment of other types of cancer. Faslodex blocks estrogen activity in the body and is a type of antiestrogen. Also called fulvestrant and ICI 182780.

fast-neutron beam radiation  (fast NOO-tron beem RAY-dee-AY-shun)
A type of radiation therapy that uses tiny particles called neutrons made by a machine called a cyclotron.

fat-soluble vitamin  (… SOL-yoo-bul VY-tuh-min)
A vitamin that can dissolve in fats and oils. Fat-soluble vitamins are absorbed along with fats in the diet and can be stored in the body’s fatty tissue. They come from plant and animal foods or dietary supplements. Vitamins A, D, E, and K are fat-soluble.

fatigue  
A condition marked by extreme tiredness and inability to function due lack of energy. Fatigue may be acute or chronic.

fatty acid  
A major component of fats that is used by the body for energy and tissue development.

fatty-replaced breast tissue  
A term used in mammography that refers to the replacement of breast tissue with fatty tissue. This commonly occurs as a woman ages.

fazarabine  
An anticancer drug that is a type of antimetabolite.

FDA  
Food and Drug Administration. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The FDA also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called Food and Drug Administration.

FdCyd  
A substance being studied in the treatment of some types of cancer. It may prevent the growth of tumors by stopping cancer cells from dividing and by killing them. It is a type of antimetabolite. Also called 5-fluoro-2-deoxycytidine.

febrile neutropenia  (FEH-brile noo-troh-PEE-nee-uh)
A condition marked by fever and decrease in the number of neutrophils in the blood. A neutrophil is a type of white blood cell that helps fight infection. Having too few neutrophils increases the risk of infection.

fecal incontinence  (FEE-kal in-KAHN-tih-nens)
Inability to hold stool in the rectum.

fecal occult blood test  (FEE-kul uh-KULT...)
FOBT. A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer. Also called FOBT.

feces  (FEE-seez)
The material in a bowel movement. Feces is made up of food that was not digested, bacteria, mucus, and cells from the intestines. Also called stool.

Femara  (FEM-uh-ruh)
A drug used to treat advanced breast cancer in postmenopausal women. Femara causes a decrease in the amount of estrogen made by the body. It is a type of aromatase inhibitor. Also called letrozole.

fenofibrate  (FEN-oh-FY-brayt)
A drug used to treat high levels of cholesterol and triglycerides in the blood. Fenofibrate is being studied in the treatment of advanced cancers in young patients and in the treatment of other conditions. It is a type of antilipidemic agent. Also called TriCor and Lofibra.

fenretinide  (fen-REH-tih-nide)
A substance being studied in the treatment and prevention of some types of cancer. Fenretinide may cause ceramide (a wax-like substance) to build up in tumor cells and kill them. It is a type of retinoid, which are substances related to vitamin A.

fenretinide LXS  (fen-REH-tih-nide…)
Fenretinide Lym-X-Sorb. A powdered form of fenretinide that is being studied in the treatment of neuroblastoma. It may be used by the body more easily than the pill form. Fenretinide may cause ceramide (a wax-like substance) to build up in tumor cells and kill them. It is a type of retinoid, which are substances related to vitamin A. Also called fenretinide Lym-X-Sorb.

fenretinide Lym-X-Sorb  (fen-REH-tih-nide…)
Fenretinide LXS. A powdered form of fenretinide that is being studied in the treatment of neuroblastoma. It may be used by the body more easily than the pill form. Fenretinide may cause ceramide (a wax-like substance) to build up in tumor cells and kill them. It is a type of retinoid, which are substances related to vitamin A. Also called fenretinide LXS.

fentanyl  (FEN-tuh-nil)
A drug used to treat moderate to severe pain that is ongoing and cannot be managed with other pain medicines. Fentanyl binds to receptors in the central nervous system to decrease pain and improve mood. It is a type of opioid analgesic. Also called Duragesic.

fentanyl sublingual spray  (FEN-tuh-nil sub-LING-wul …)
A form of the drug fentanyl that is sprayed under the tongue and then absorbed into the blood. It is being studied in the treatment of breakthrough pain (pain that occurs even when pain-control medication is already being used) in cancer patients. Fentanyl is a type of opioid analgesic.

fertile  (FER-tul)
Able to produce children.

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

ferumoxtran-10  (fayr-yoo-MOX-tran…)
A substance being studied as a way of improving magnetic resonance imaging (MRI) in diagnosing cancer and finding lymph nodes to which cancer has spread. Ferumoxtran-10 is made of nanoparticles (ultrasmall pieces) of iron oxide coated with dextran (a type of sugar). It is injected into the blood of the patient and the particles collect in lymph nodes, liver, spleen, or brain tissue where they can be seen using MRI. Ferumoxtran-10 later breaks down and passes from the body in urine.

ferumoxytol  
A nanoparticle form of iron made in the laboratory that is being studied for use in iron replacement therapy, and as a contrast agent for magnetic resonance imaging. Contrast agents are substances that are injected into the body and taken up by certain tissues, making the tissues easier to see in imaging scans.

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

fever  (FEE-ver)
An increase in body temperature above normal (98.6 degrees F), usually caused by disease.

fexofenadine  (fex-oh-FEN-uh-deen)
A drug used to treat certain allergy symptoms. It blocks a chemical released during an allergic response that causes itching, sneezing, runny nose, wheezing, and watery eyes. It is a type of antihistamine. Also called Allegra.

fiber  (FY-ber)
In food, fiber is the part of fruits, vegetables, legumes, and whole grains that cannot be digested. The fiber in food may help prevent cancer. In the body, fiber refers to tissue made of long threadlike cells, such as muscle fiber or nerve fiber.

fiberoptic  (FY-ber-OP-tik)
Describes the use of a coated, thin, clear, glass or plastic fiber that can carry light and send information, including images. In medicine, flexible fiberoptic instruments are used to look inside the body. Fiberoptics are also used to deliver laser light to tumors injected with a type of drug that kills cancer cells when it is exposed to laser light.

fibrin sealant  
A type of surgical glue that is made from human blood-clotting proteins, and that is used during surgery to control bleeding.

fibroadenoma  (FY-broh-a-deh-NOH-muh)
A benign (noncancerous) tumor that usually forms in the breast from both fibrous and glandular tissue. Fibroadenomas are the most common benign breast tumors.

fibroblast  
A connective tissue cell that makes and secretes collagen proteins.

fibrocystic breast changes  (FY-broh-SISS-tik)
A common condition marked by benign (noncancerous) changes in breast tissue. These changes may include irregular lumps or cysts, breast discomfort, sensitive nipples, and itching. These symptoms may change throughout the menstrual cycle and usually stop after menopause. Also called benign breast disease, fibrocystic breast disease, and mammary dysplasia.

fibrocystic breast disease  (FY-broh-SISS-tik brest dih-ZEEZ )
A common condition marked by benign (noncancerous) changes in breast tissue. These changes may include irregular lumps or cysts, breast discomfort, sensitive nipples, and itching. These symptoms may change throughout the menstrual cycle and usually stop after menopause. Also called benign breast disease, fibrocystic breast changes, and mammary dysplasia.

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

fibromatosis  (fy-BROH-muh-TOH-sis)
A condition in which multiple fibromas develop. Fibromas are tumors (usually benign) that affect connective tissue.

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.

fibrous  
Containing or resembling fibers.

fifth cranial nerve  
The main sensory nerve of the head and face, and the motor nerve of the muscles used in chewing. Also called the trigeminal nerve.

FIHP  
Familial isolated hyperparathyroidism. A rare inherited condition in which one or more tumors form in the parathyroid glands (four pea-sized organs found on the thyroid) and cause them to make too much parathyroid hormone. The increased parathyroid hormone causes a loss of calcium from the bones and too much calcium in the blood. Also called familial isolated hyperparathyroidism.

filgrastim  
A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that is a type of hematopoietic (blood-forming) agent. Also called granulocyte colony-stimulating factor and G-CSF.

filgrastim-SD/01  (fil-GRAS-tim)
A drug used to increase numbers of white blood cells in patients who are receiving chemotherapy. It is a type of colony-stimulating factor. Also called pegfilgrastim and Neulasta.

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  (fi-NAS-ta-ride)
A drug used to reduce the amount of male hormone (testosterone) produced by the body.

fine-needle aspiration biopsy  (... NEE-dul as-per-AY-shun BY-op-see)
The removal of tissue or fluid with a thin needle for examination under a microscope. Also called FNA biopsy.

first-degree relative  
The parents, brothers, sisters, or children of an individual.

first-line therapy  (... THAYR-uh-pee)
The first treatment for a disease or condition. In patients with cancer, first-line therapy can be surgery, chemotherapy, radiation therapy, or a combination of these therapies. Also called primary therapy and primary treatment.

FISH  
A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light. Also called fluorescence in situ hybridization.

fistula  (fis-CHUH-luh)
An abnormal opening or passage between two organs or between an organ and the surface of the body. Fistulas may be caused by injury, infection, or inflammation, or may be created during surgery.

five element acupuncture  (five EL-eh-ment AK-yoo-PUNK-cher)
An ancient form of acupuncture based on the principle that there are five universal elements (wood, fire, earth, metal, and water) that affect a person's emotions, personality, health, and response to treatment. Each person is affected by one element more than the others. Also called traditional acupuncture.

five-year survival rate  (... ser-VY-vul ...)
The percentage of people in a study or treatment group who are alive five years after they were diagnosed with or treated for a disease, such as cancer. The disease may or may not have come back.

FK463  
An antibiotic/antifungal drug used to treat infection.

Flagyl  
A drug that is used to treat infection and is being studied in the treatment of cancer. It is type of antibacterial, antiprotozoal, and anthelmintic. Also called metronidazole.

flavonoid  
A member of a group of substances found in many plants and plant-based foods. Flavonoids have shown antioxidant effects.

flavopiridol  
A substance being studied as an anticancer drug. It is a type of flavonoid.

flaxseed  
The seed of the flax plant. It is a rich source of omega-3 fatty acid, fiber, and a compound called lignin. It is being studied in the prevention of prostate cancer. Also called linseed.

flecainide  
A drug 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.

Flomax  (FLOH-max)
A drug used to treat urinary problems caused by an enlarged prostate. Flomax relaxes the muscles of the prostate and bladder, which helps the flow of urine. It is a type of alpha blocker. Also called tamsulosin and tamsulosin hydrochloride.

flow cytometry  
A method of measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light.

floxuridine  
A drug used in the treatment of cancer. It is a type of antimetabolite.

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.

Fludara  (floo-DAR-uh)
A drug used to treat B-cell chronic lymphocytic leukemia (CLL) that has not responded to treatment with other anticancer drugs or that has gotten worse. It is also being studied in the treatment of other types of cancer. Fludara blocks cells from making DNA and may kill cancer cells. It is a type of purine antagonist and a type of ribonucleotide reductase inhibitor. Also called fludarabine phosphate.

fludarabine  (floo-DAR-uh-been)
The active ingredient in a drug used to treat B-cell chronic lymphocytic leukemia (CLL) that has not responded to treatment with other anticancer drugs or that has gotten worse. Fludarabine blocks cells from making DNA and may kill cancer cells. It is a type of purine antagonist and a type of ribonucleotide reductase inhibitor.

fludarabine phosphate  (floo-DAR-uh-been FOS-fayt)
A drug used to treat B-cell chronic lymphocytic leukemia (CLL) that has not responded to treatment with other anticancer drugs or that has gotten worse. It is also being studied in the treatment of other types of cancer. Fludarabine phosphate blocks cells from making DNA and may kill cancer cells. It is a type of purine antagonist and a type of ribonucleotide reductase inhibitor. Also called Fludara.

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.

fluid  
Liquid.

fluorescence in situ hybridization  (floor-EH-sents in SY-too HY-brih-dih-ZAY-shun)
A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light. Also called FISH.

fluoride  
A substance that helps prevent tooth decay. Fluoride may be naturally present in or may be added to drinking water. It may also be applied to the teeth in a gel, toothpaste, or a rinse.

fluorine F 18 EF5  (FLOR-een...)
A substance being studied in positron emission tomography (PET) imaging to detect tumor hypoxia (a low level of oxygen in the tumor). This may help predict how the tumor will respond to treatment. It is a type of radiopharmaceutical. Also called 18F-EF5.

fluorine F 18 FEQA  (FLOOR-een …)
A radioactive substance being studied in positron emission tomography (PET) imaging to detect cancer and to monitor the response of some types of cancer to treatment. Fluorine F 18 FEQA attaches to the epidermal growth factor receptor (EGFR) found on the surface of some tumor cells. It is a type of radiopharmaceutical.

fluoropyrimidine  
One of a group of substances used to treat cancer. A fluoropyrimidine is a type of antimetabolite. Examples are capecitabine, floxuridine, and fluorouracil (5-FU).

fluoroquinolone  (flur-oh-KWIH-nuh-lone)
A type of drug used to prevent and treat infections.

fluoroscope  (FLOOR-oh-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.

fluorothymidine F 18  (FLOOR-oh-THY-mih-DEEN…)
A radioactive substance being studied in the diagnosis of cancer. Fluorothymidine F 18 is injected into the blood and builds up in cells that are dividing, including cancer cells. The radiation that it gives off as it decays (breaks down) helps make clear pictures of tumors during positron emission tomography (PET) scans. It is a type of radiopharmaceutical. Also called 3’-deoxy-3’-(18F) fluorothymidine and 18F-FLT.

fluorouracil  (floor-oh-YOOR-a-sil)
A drug used as a treatment for cancer. It is a type of antimetabolite. Also called 5-FU.

fluoxetine  
A drug used to treat depression. It is a type of antidepressant.

fluphenazine  (floo-FEH-nuh-ZEEN)
A drug that is used to treat mental and emotional disorders and is being studied in the treatment of multiple myeloma. Fluphenazine may stop tumor growth by keeping myeloma cells from dividing and causing them to die. It is a type of antipsychotic. Also called fluphenazine hydrochloride.

fluphenazine hydrochloride  (floo-FEH-nuh-ZEEN HY-droh-KLOR-ide)
A drug that is used to treat mental and emotional disorders and is being studied in the treatment of multiple myeloma. Fluphenazine hydrochloride may stop tumor growth by keeping myeloma cells from dividing and causing them to die. It is a type of antipsychotic. Also called fluphenazine.

flutamide  (FLOO-ta-mide)
An anticancer drug that is a type of antiandrogen.

fluvoxamine  (floo-VOX-uh-meen)
A drug used to treat obsessive-compulsive disorder. It is a type of antidepressant agent and selective serotonin reuptake inhibitor (SSRI). Also called Luvox.

FMISO  
A radioactive substance being studied as an imaging agent in head and neck cancers and other types of cancer. It binds to large molecules in tumor cells that have a low level of oxygen. Radiation given off by FMISO is detected by a PET scan. The amount of FMISO in the tumor may help decide the best treatment and help predict whether the cancer will come back after treatment. FMISO is a type of radioimaging agent. Also called 18F-fluoromisonidazole and 18F-MISO.

FNA biopsy  (... BY-op-see)
The removal of tissue or fluid with a thin needle for examination under a microscope. Also called fine-needle aspiration biopsy.

FOBT  
Fecal occult blood test. A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer. Also called fecal occult blood test.

focal  
In terms of cancer, limited to a specific area.

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

folate antagonist  
A substance that blocks the activity of folic acid. Folate antagonists are used to treat cancer. Also called antifolate.

FOLFOX  
An abbreviation for a type of combination chemotherapy that is used to treat colorectal cancer. It includes fluorouracil, leucovorin, and oxaliplatin.

folic acid  (FOH-lik A-sid)
A B-complex vitamin being studied as a cancer prevention agent. Also called folate.

folinic acid  (foh-LIN-ik A-sid)
The active ingredient in a drug used to reduce the toxic effects of folic acid antagonists (substances that block the action of folic acid), especially the anticancer drug methotrexate. It is also used to treat anemia and it is used with fluorouracil to treat symptoms of advanced colorectal cancer. It is also being studied in the treatment of other types of cancer and other conditions. Folinic acid is a form of folic acid, a B-complex vitamin that the body needs to make red blood cells and to function and stay healthy. Folinic acid is a type of chemoprotective agent and a type of chemosensitizing agent. Also called leucovorin and Citrovorum factor.

follicle  (FOL-i-kul)
A sac or pouch-like cavity.

follicular large cell lymphoma  (fuh-LIH-kyoo-ler larj sel lim-FOH-muh)
A rare type of non-Hodgkin 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.

follicular lymphoma  (fuh-LIH-kyoo-ler lim-FOH-muh)
A type of B-cell non-Hodgkin lymphoma (cancer of the immune system) that is usually indolent (slow-growing). The tumor cells grow as groups to form nodules. There are several subtypes of follicular lymphoma.

follicular mixed cell lymphoma  (fuh-LIH-kyoo-ler miks'd sel lim-FOH-muh)
An indolent (slow-growing) type of B-cell non-Hodgkin lymphoma (cancer of the lymphatic system) in which there are both small and large cancer cells.

follicular thyroid cancer  (fuh-LIH-kyoo-ler THY-royd KAN-ser)
Cancer that forms in follicular cells in the thyroid. It grows slowly and is highly treatable.

follow-up  
Monitoring a person's health over time after treatment. This includes keeping track of the health of people who participate in a clinical study or clinical trial for a period of time, both during the study and after the study ends.

fondaparinux  (fon-duh-PAYR-ih-nux)
A drug used to prevent blood clots from forming inside blood vessels in the leg. It is being studied in the prevention of blood clots in some cancer patients, including women having surgery for cancer of the reproductive tract. It is a type of anticoagulant. Also called fondaparinux sodium and Arixtra.

fondaparinux sodium  (fon-duh-PAYR-ih-nux SOH-dee-um)
A drug used to prevent blood clots from forming inside blood vessels in the leg. It is being studied in the prevention of blood clots in some cancer patients, including women having surgery for cancer of the reproductive tract. It is a type of anticoagulant. Also called fondaparinux and Arixtra.

Food and Drug Administration  
FDA. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

foreskin  (FOR-skin)
The loose skin that covers the head of the penis.

formaldehyde  (for-MAL-duh-hide)
A chemical used in manufacturing and chemical industries, and as a preservative by anatomists, embalmers, and pathologists. Being exposed to formaldehyde may increase the risk of developing leukemia and brain cancer.

forodesine  (FOR-oh-deh-seen)
A substance being studied in the treatment of some types of leukemia and lymphoma. It is a type of purine nucleoside phosphorylase (PNP) inhibitor. Also called BCX-1777 and forodesine hydrochloride.

forodesine hydrochloride  (FOR-oh-deh-seen HY-droh-KLOR-ide)
A substance being studied in the treatment of some types of leukemia and lymphoma. It is a type of purine nucleoside phosphorylase (PNP) inhibitor. Also called forodesine and BCX-1777.

Fosamax  (FAH-suh-max)
A drug used to treat certain bone conditions, such as osteoporosis and Paget disease of the bone. It is also being studied in the treatment of hypercalcemia (high levels of calcium in the blood) and bone pain caused by cancer. Fosamax slows the breakdown of bone and prevents the loss of calcium. It is a type of bisphosphonate. Also called alendronate sodium.

fotemustine  
A substance being studied in the treatment of brain tumors and metastatic melanoma of the eye. It is a type of nitrosourea.

FR901228  
A substance being studied in the treatment of cancer. FR901228 is a type of depsipeptide and histone deacetylase inhibitor. Also called romidepsin.

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

Fragmin  (FRAG-min)
A drug used to prevent blood clots from forming or to treat blood clots that have formed in patients with cancer or other conditions. Fragmin is a type of anticoagulant. Also called dalteparin and dalteparin sodium.

fragrance  (FRAY-grants)
A pleasant, sweet odor.

frankincense tree  (FRAN-kin-SENTS…)
A tree that belongs to the incense tree family. The tree’s amber-colored resin is used in incense. The resin has anti-inflammatory effects and has been used to treat arthritis, asthma, and ulcerative colitis. It is also being studied in the treatment of brain tumors. Also called Boswellia serrata.

free radical  
A highly reactive chemical that often contains oxygen and is produced when molecules are split to give products that have unpaired electrons (a process 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.

frontal sinus  (FRUN-tul SY-nus)
A type of paranasal sinus (a hollow space in the bones around the nose). There are two, large frontal sinuses in the frontal bone, which forms the lower part of the forehead and reaches over the eye sockets and eyebrows. The frontal sinuses are lined with cells that make mucus to keep the nose from drying out.

fruit acid  (FROOT A-sid)
One of a group of substances that are found in several types of fruit and in milk. They are used in skin care products to reduce wrinkles and soften the skin. Examples of fruit acids are glycolic acid, lactic acid, and citric acid. Also called alpha hydroxyl acid and AHA.

Ftorafur  
A substance being studied in the treatment of some types of cancer. It is a combination of tegafur and uracil. The tegafur is taken up by the cancer cells and breaks down into 5-FU, a substance that kills tumor cells. The uracil causes higher amounts of 5-FU to stay inside the cells and kill them. Ftorafur is a type of antimetabolite. Also called tegafur-uracil, UFT, and Uftoral.

fulguration  (ful-guh-RAY-shun)
A procedure to destroy tissue (such as a tumor) using an electric current. Also called electrofulguration.

fulvestrant  (fool-VES-trant)
A drug used to treat certain types of breast cancer in postmenopausal women. It is also being studied in the treatment of other types of cancer. Fulvestrant blocks estrogen activity in the body and is a type of antiestrogen. Also called Faslodex and ICI 182780.

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.

functioning tumor  (FUNK-shuh-ning TOO-mer)
A tumor that is found in endocrine tissue and makes hormones (chemicals that travel in the bloodstream and control the actions of other cells or organs).

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.

fungating lesion  
A type of skin lesion that is marked by ulcerations (breaks on the skin or surface of an organ) and necrosis (death of living tissue) and that usually has a bad smell. This kind of lesion may occur in many types of cancer, including breast cancer, melanoma, and squamous cell carcinoma, and especially in advanced disease.

fungus  
A plant-like organism that does not make chlorophyll. Mushrooms, yeasts, and molds are examples. The plural is fungi.

fusion gene  (FYOO-zhun JEEN)
A gene made by joining parts of two different genes. Fusion genes may occur naturally in the body by transfer of DNA between chromosomes. For example, the BCR-ABL gene found in some types of leukemia is a fusion gene. Fusion genes can also be made in the laboratory by combining genes or parts of genes from the same or different organisms.

fusion protein  (FYOO-zhun PROH-teen)
A protein made from a fusion gene, which is created by joining parts of two different genes. Fusion genes may occur naturally in the body by transfer of DNA between chromosomes. For example, the BCR-ABL gene found in some types of leukemia is a fusion gene that makes the BCR-ABL fusion protein. Fusion genes and proteins can also be made in the laboratory by combining genes or parts of genes from the same or different organisms.

Back to Top

A Service of the National Cancer Institute
Department of Health and Human Services National Institutes of Health USA.gov