G-CSF

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 filgrastim and granulocyte colony-stimulating factor.

gabapentin

A substance that is being studied as a treatment for relieving hot flashes in women with breast cancer. It belongs to the family of drugs called anticonvulsants.

GAD

A condition marked by excessive worry and feelings of fear, dread, and uneasiness that last six months or longer. Other symptoms of GAD include being restless, being tired or irritable, muscle tension, not being able to concentrate or sleep well, shortness of breath, fast heartbeat, sweating, and dizziness. Also called generalized anxiety disorder.

gadobenate dimeglumine

A drug used in MRI to help make clear pictures of blood vessels in the brain, spine, and nearby tissues. It is also being studied as a way to find abnormal areas in the liver and other organs and to help diagnose cancer. Gadobenate dimeglumine is a type of contrast agent. Also called MultiHance.

gadolinium

A metal element that is used in magnetic resonance imaging (MRI) and other imaging methods. It is a contrast agent, which helps show abnormal tissue in the body during imaging with a special machine.

gadolinium texaphyrin

A substance that is being studied in the treatment of cancer. It may make tumor cells more sensitive to radiation therapy, improve tumor images using magnetic resonance imaging (MRI), and kill cancer cells. It is a type of metalloporphyrin complex. Also called motexafin gadolinium.

gadopentetate dimeglumine

A substance used in magnetic resonance imaging (MRI) to help make clear pictures of the brain, spine, heart, soft tissue of joints, and inside bones. Gadopentetate dimeglumine is being studied in the diagnosis of cancer. It is a type of contrast agent. Also called Gd-DTPA and Magnevist.

Gail model

A computer program that uses personal and family medical history information to estimate a womanƒ??s chance of developing breast cancer. Also called Gail risk model.

Gail risk model

A computer program that uses personal and family medical history information to estimate a womanƒ??s chance of developing breast cancer. Also called Gail model.

galiximab

A substance being studied in the treatment of follicular non-Hodgkin lymphoma. It binds to the protein CD80, which is found on certain normal white blood cells and on white blood cells that are cancer. It is a type of monoclonal antibody.

gallbladder

The pear-shaped organ found below the liver. Bile is concentrated and stored in the gallbladder.

gallbladder cancer

Cancer that forms in tissues of the gallbladder. The gallbladder is a pear-shaped organ below the liver that collects and stores bile (a fluid made by the liver to digest fat). Gallbladder cancer begins in the innermost layer of tissue and spreads through the outer layers as it grows.

gallium nitrate

A drug that lowers blood calcium. Used as treatment for hypercalcemia (too much calcium in the blood) and for cancer that has spread to the bone (bone metastases).

gallium scan

A procedure to detect areas of the body where cells are dividing rapidly. It is used to locate cancer cells or areas of inflammation. A very small amount of radioactive gallium is injected into a vein and travels through the bloodstream. The gallium is taken up by rapidly dividing cells in the bones, tissues, and organs and is detected by a scanner.

gallstone

Solid material that forms in the gallbladder or common bile duct. Gallstones are made of cholesterol or other substances found in the gallbladder. They may occur as one large stone or as many small ones, and vary from the size of a golf ball to a grain of sand. Also called cholelith.

galvanic skin response

A change in the heat and electricity passed through the skin by nerves and sweat. Galvanic skin response increases in certain emotional states and during hot flashes that happen with menopause. Also called electrodermal response and skin conduction.

gamma irradiation

A type of radiation therapy that uses gamma radiation. Gamma radiation is a type of high-energy radiation that is different from x-rays.

Gamma Knife therapy

A treatment using gamma rays, a type of high-energy radiation that can be tightly focused on small tumors or other lesions in the head or neck, so very little normal tissue receives radiation. The gamma rays are aimed at the tumor from many different angles at once, and deliver a large dose of radiation exactly to the tumor in one treatment session. This procedure is a type of stereotactic radiosurgery. Gamma Knife therapy is not a knife and is not surgery. Gamma Knife is a registered trademark of Elekta Instruments, Inc.

gamma ray

A type of high-energy radiation that is different from an x-ray.

ganciclovir

An antiviral agent used to prevent or treat cytomegalovirus infections that may occur when the body's immune system is suppressed. In gene therapy, ganciclovir is used with an altered herpes simplex virus-1 gene to kill advanced melanoma cells and brain tumor cells.

ganglioside

A complex molecule that contains both lipids (fats) and carbohydrates (sugars) and is found in the plasma (outer) membrane of many kinds of cells. Several different types of gangliosides have been identified.

Gardasil

A vaccine used to prevent anal, cervical, vulvar, and vaginal cancer caused by human papillomavirus (HPV) types 16 and 18 and genital warts caused by HPV types 6 and 11. It is also used to prevent lesions that are caused by these viruses and that can lead to anal, cervical, vulvar, or vaginal cancer. Gardasil is used in males and females aged 9-26 years. Gardasil is being studied in the treatment of other medical conditions. Also called quadrivalent human papillomavirus (types 6, 11, 16, and 18) recombinant vaccine and recombinant human papillomavirus quadrivalent vaccine.

garden heliotrope

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, Mexican valerian, Pacific valerian, valerian, Valeriana officinalis, and Valerianae radix.

garden 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 heliotrope, Indian valerian, Mexican valerian, Pacific valerian, valerian, Valeriana officinalis, and Valerianae radix.

garlic

A European plant that has a bulb used to flavor food. It has also been used in some cultures to treat certain medical conditions including high cholesterol, high blood pressure, infections, and cancer. The scientific name is Allium sativum.

gastrectomy

An operation to remove all or part of the stomach.

gastric

Having to do with the stomach.

gastric acid

Acid that is released into the stomach from glands in the stomach wall. It helps digest food. Gastric acid is made of hydrochloric acid.

gastric acid secretion test

A test used to measure the amount of gastric acid made by the stomach. The patient receives an injection of the hormone gastrin or insulin. A tube is put through the nose or throat into the stomach and samples are taken from the stomach and sent to a laboratory for testing. Also called stomach acid stimulation test and stomach acid test.

gastric atrophy

A condition in which the stomach muscles shrink and become weak. The digestive (peptic) glands may also shrink, resulting in a lack of digestive juices.

gastric cancer

Cancer that forms in tissues lining the stomach. Also called stomach cancer.

gastric feeding tube

A tube that is inserted through the nose, down the throat and esophagus, and into the stomach. It can be used to give drugs, liquids, and liquid food, or used to remove substances from the stomach. Giving food through a gastric feeding tube is a type of enteral nutrition. Also called nasogastric tube and NG tube.

gastric mucosal hypertrophy

A condition marked by inflammation and ulcers (breaks on the skin or on the surface of an organ) of the mucosa (inner lining) of the stomach and by overgrowth of the cells that make up the mucosa. Symptoms include vomiting, diarrhea, and weight loss. Patients with gastric mucosal hypertrophy may be at a higher risk of stomach cancer. Also called giant hypertrophic gastritis and M??n??trier disease.

gastric reflux

The backward flow of stomach acid contents into the esophagus (the tube that connects the mouth to the stomach). Also called esophageal reflux and gastroesophageal reflux.

gastrin

A hormone released from special cells in the lining of the stomach after eating. Gastrin causes the stomach to release an acid that helps digest food.

gastrinoma

A tumor that causes overproduction of gastric acid. It usually begins in the duodenum (first part of the small intestine that connects to the stomach) or the islet cells of the pancreas. Rarely, it may also begin in other organs, including the stomach, liver, jejunum (the middle part of the small intestine), biliary tract (organs and ducts that make and store bile), mesentery, or heart. It is a type of neuroendocrine tumor, and it may metastasize (spread) to the liver and the lymph nodes.

gastritis

Inflammation of the lining of the stomach.

gastroenteritis

Inflammation of the lining of the stomach and the intestines. Symptoms may include nausea, vomiting, diarrhea, and abdominal cramps (dull or sharp pains). Gastroenteritis may be caused by infection with bacteria, parasites, or viruses. It may also be caused by food poisoning, allergic reactions, or reactions to certain medicines or foods.

gastroenterologist

A doctor who specializes in diagnosing and treating disorders of the digestive system.

gastroesophageal junction

The place where the esophagus is connected to the stomach.

gastroesophageal reflux

The backward flow of stomach acid contents into the esophagus (the tube that connects the mouth to the stomach). Also called esophageal reflux and gastric reflux.

gastrointestinal

Refers to the stomach and intestines. Also called GI.

gastrointestinal carcinoid tumor

An indolent (slow-growing) cancer that forms in cells that make hormones in the lining of the gastrointestinal tract (the stomach and intestines). It usually occurs in the appendix (a small fingerlike pouch of the large intestine), small intestine, or rectum. Having gastrointestinal carcinoid tumor increases the risk of forming other cancers of the digestive system.

gastrointestinal stromal tumor

A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. It can be benign or malignant. Also called GIST.

gastrointestinal tract

The stomach and intestines. The gastrointestinal tract is part of the digestive system, which also includes the salivary glands, mouth, esophagus, liver, pancreas, gallbladder, and rectum.

gastroscope

A thin, tube-like instrument used to examine the inside of the stomach. A gastroscope has a light and a lens for viewing and may have a tool to remove tissue.

gastroscopy

Examination of the inside of the stomach using a gastroscope passed through the mouth and esophagus. A gastroscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called upper endoscopy.

gastrostomy tube

A tube inserted through the wall of the abdomen directly into the stomach. It allows air and fluid to leave the stomach and can be used to give drugs and liquids, including liquid food, to the patient. Giving food through a gastrostomy tube is a type of enteral nutrition. Also called PEG tube and percutaneous endoscopic tube.

GBM

A fast-growing type of central nervous system tumor that forms from glial (supportive) tissue of the brain and spinal cord and has cells that look very different from normal cells. GBM usually occurs in adults and affects the brain more often than the spinal cord. Also called glioblastoma, glioblastoma multiforme, and grade IV astrocytoma.

GC1008

A monoclonal antibody being studied in the treatment of kidney cancer, melanoma, and pulmonary fibrosis. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. GC1008 binds to the protein transforming growth factor-beta (TGF??) and may block the growth of cancer cells that make it. Also called anti-TGF-beta monoclonal antibody GC1008.

GCP

An international set of guidelines that helps make sure that the results of a clinical trial are reliable and that the patients are protected. GCP covers the way a clinical trial is designed, conducted, performed, monitored, audited, recorded, analyzed, and reported. Also called Good Clinical Practice.

Gd-DTPA

A substance used in magnetic resonance imaging (MRI) to help make clear pictures of the brain, spine, heart, soft tissue of joints, and inside bones. Gd-DTPA is being studied in the diagnosis of cancer. It is a type of contrast agent. Also called gadopentetate dimeglumine and Magnevist.

GDC-0449

A substance being studied in the treatment of cancer. It blocks a type of protein involved in tissue growth and repair and may block the growth of cancer cells. It is a type of Hedgehog signaling pathway antagonist.

gefitinib

A drug that is used to treat certain types of non-small cell lung cancer and is being studied in the treatment of other types of cancer. It is a type of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. Also called Iressa and ZD1839.

gel electrode

A device that uses a gel to carry an electric current from the skin to a measuring instrument. A sticky patch may hold the gel electrode on the skin so that the electrical activity of the heart or brain can be measured.

Gelclair

A gel used to lessen pain from mouth sores caused by chemotherapy or radiation therapy, oral surgery, braces, or disease. Gelclair is being studied in the treatment of pain caused by mouth sores in children receiving cancer treatment. It forms a thin layer over the surface of the mouth and throat to prevent irritation while eating, drinking, and talking. Also called polyvinylpyrrolidone-sodium hyaluronate gel.

geldanamycin analog

An antineoplastic antibiotic drug that belongs to the family of drugs called ansamycins.

GEM 231

A drug that may inhibit the growth of malignant tumors.

GEM640

A substance being studied in the treatment of cancer. GEM640 may kill cancer cells by blocking the production of a protein called XIAP that helps cells live longer. It also makes cancer cells more sensitive to anticancer drugs. It is a type of antisense oligonucleotide, and a type of chemosensitizing agent. Also called AEG35156.

gemcitabine

The active ingredient in a drug that is used to treat pancreatic cancer that is advanced or has spread. It is also used with other drugs to treat breast cancer that has spread, advanced ovarian cancer, and non-small cell lung cancer that is advanced or has spread. It is also being studied in the treatment of other types of cancer. Gemcitabine blocks the cell from making DNA and may kill cancer cells. It is a type of antimetabolite

gemcitabine hydrochloride

A drug used to treat pancreatic cancer that is advanced or has spread. It is also used with other drugs to treat breast cancer that has spread, advanced ovarian cancer, and non-small cell lung cancer that is advanced or has spread. It is also being studied in the treatment of other types of cancer. Gemcitabine hydrochloride blocks the cell from making DNA and may kill cancer cells. Also called Gemzar.

gemcitabine-erlotinib regimen

A chemotherapy combination used for the treatment of locally advanced and metastatic pancreatic cancer . It includes the drugs gemcitabine hydrochloride and erlotinib hydrochloride. Also called gemcitabine-Tarceva regimen.

gemcitabine-Tarceva regimen

A chemotherapy combination used for the treatment of locally advanced and metastatic pancreatic cancer . It includes the drugs gemcitabine hydrochloride and erlotinib hydrochloride. Also called gemcitabine-erlotinib regimen.

gemcitabine/cisplatin

A chemotherapy combination used to treat malignant mesothelioma, advanced non-small cell lung cancer, advanced bladder cancer, advanced cervical cancer, pancreatic cancer, and epithelial ovarian cancer. It is also being studied in the treatment of other types of cancer. It includes the drugs gemcitabine hydrochloride and cisplatin. Also called gemcitabine/cisplatin regimen.

gemcitabine/cisplatin regimen

A chemotherapy combination used to treat malignant mesothelioma, advanced non-small cell lung cancer, advanced bladder cancer, advanced cervical cancer, pancreatic cancer, and epithelial ovarian cancer. It is also being studied in the treatment of other types of cancer. It includes the drugs gemcitabine hydrochloride and cisplatin. Also called gemcitabine/cisplatin.

gemtuzumab

A monoclonal antibody combined with a toxic substance that is used to treat certain types of acute myeloid leukemia in older patients and is being studied in the treatment of other types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Gemtuzumab is a type of antibody-drug conjugate. Also called gemtuzumab ozogamicin and Mylotarg.

gemtuzumab ozogamicin

A monoclonal antibody combined with a toxic substance that is used to treat certain types of acute myeloid leukemia in older patients and is being studied in the treatment of other types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Gemtuzumab ozogamicin is a type of antibody-drug conjugate. Also called gemtuzumab and Mylotarg.

Gemzar

A drug used to treat pancreatic cancer that is advanced or has spread. It is also used with other drugs to treat breast cancer that has spread, advanced ovarian cancer, and non-small cell lung cancer that is advanced or has spread. It is also being studied in the treatment of other types of cancer. Gemzar blocks the cell from making DNA and may kill cancer cells. Also called gemcitabine hydrochloride.

Genasense

A substance being studied in the treatment of cancer. It may kill cancer cells by blocking the production of a protein that makes cancer cells live longer and by making them more sensitive to anticancer drugs. It is a type of antisense oligodeoxyribonucleotide. Also called augmerosen, bcl-2 antisense oligodeoxynucleotide G3139, and oblimersen sodium.

gene

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

gene amplification

An increase in the number of copies of a gene. There may also be an increase in the RNA and protein made from that gene. Gene amplification is common in cancer cells, and some amplified genes may cause cancer cells to grow or become resistant to anticancer drugs. Genes may also be amplified in the laboratory for research purposes.

gene deletion

The loss of all or a part of a gene. There may also be a change in the RNA and protein made from that gene. Certain gene deletions are found in cancer and in other genetic diseases and abnormalities.

gene expression

The process by which a gene gets turned on in a cell to make RNA and proteins. Gene expression may be measured by looking at the RNA, or the protein made from the RNA, or what the protein does in a cell.

gene expression profile

Information about all messenger RNAs that are made in various cell types. A gene expression profile may be used to find and diagnose a disease or condition and to see how well the body responds to treatment. Gene expression profiles may be used in personalized medicine.

gene therapy

Treatment that alters a gene. In studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to fight the disease or to make the cancer cells more sensitive to other kinds of therapy.

gene transfer

The insertion of genetic material into a cell.

gene-modified

Cells that have been altered to contain different genetic material than they originally contained.

general anesthesia

A temporary loss of feeling and a complete loss of awareness that feels like a very deep sleep. It is caused by special drugs or other substances called anesthetics. General anesthesia keeps patients from feeling pain during surgery or other procedures.

generalized anxiety disorder

A condition marked by excessive worry and feelings of fear, dread, and uneasiness that last six months or longer. Other symptoms of generalized anxiety disorder include being restless, being tired or irritable, muscle tension, not being able to concentrate or sleep well, shortness of breath, fast heartbeat, sweating, and dizziness. Also called GAD.

generic

Official nonbrand names by which medicines are known. Generic names usually refer to the chemical name of the drug.

genetic

Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

genetic analysis

The study of a sample of DNA to look for mutations (changes) that may increase risk of disease or affect the way a person responds to treatment.

genetic counseling

A communication process between a specially trained health professional and a person concerned about the genetic risk of disease. The person's family and personal medical history may be discussed, and counseling may lead to genetic testing.

genetic infantile agranulocytosis

An inherited disorder in which there is a lower-than-normal number of neutrophils (a type of white blood cell that is important in fighting infections). Infants with the disorder get infections caused by bacteria, and are at an increased risk of acute myelogenous leukemia (AML) or myelodysplasia (a bone marrow disorder). Also called congenital neutropenia, infantile genetic agranulocytosis, Kostmann disease, Kostmann neutropenia, and Kostmann syndrome.

genetic marker

Alteration in DNA that may indicate an increased risk of developing a specific disease or disorder.

genetic marker of susceptibility

A specific change in a personƒ??s DNA that makes the person more likely to develop certain diseases such as cancer.

genetic predisposition

An inherited increase in the risk of developing a disease. Also called genetic susceptibility.

genetic profile

Information about specific genes, including variations and gene expression, in an individual or in a certain type of tissue. A genetic profile may be used to help diagnose a disease or learn how the disease may progress or respond to treatment with drugs or radiation.

genetic susceptibility

An inherited increase in the risk of developing a disease. Also called genetic predisposition.

genetic testing

Analyzing DNA to look for a genetic alteration that may indicate an increased risk for developing a specific disease or disorder.

genetics

The study of genes and heredity. Heredity is the passing of genetic information and traits (such as eye color and an increased chance of getting a certain disease) from parents to offspring.

genistein

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

genital

Refers to the genitalia (external and internal sex organs and glands).

genital wart

A raised growth on the surface of the genitals caused by human papillomavirus (HPV) infection. The HPV in genital warts is very contagious and can be spread by skin-to-skin contact, usually during oral, anal, or genital sex with an infected partner. Also called condyloma.

genitourinary system

The parts of the body that play a role in reproduction, getting rid of waste products in the form of urine, or both.

genome

The complete genetic material of an organism.

genome-wide association study

A study that compares the complete DNA of people with a disease or condition to the DNA of people without the disease or condition. These studies find the genes involved in a disease, and may help prevent, diagnose, and treat the disease. Also called GWAS, WGA study, and whole genome association study.

genomic profile

Information about all the genes in an organism, including variations, gene expression, and the way those genes interact with each other and with the environment. A genomic profile may be used to discover why some people get certain diseases while other people do not, or why people respond differently to the same drug.

genomics

The study of the complete genetic material, including genes and their functions, of an organism.

geranium

A type of plant that is native to southern Africa and has white, pink, purple, or red flowers and 3- to 5-lobed leaves. An essential oil that smells like roses is taken from the leaves and used in perfume, in mosquito repellants, and in aromatherapy to treat skin problems and to reduce stress. The scientific name is Pelargonium graveolens. Also called pelargonium.