Cancer and blood disorder glossary

A

Absolute neutrophil count

A measure of the number of neutrophils in the blood. Neutrophils are a type of white blood cell. They help the body…

Active surveillance

Closely watching a patient’s condition but not giving any treatment unless there are changes in test results that show the condition is…

Acute lymphoblastic leukemia

A type of leukemia (blood cancer) that comes on quickly and is fast growing. In acute lymphoblastic leukemia, there are too many…

Acute myeloid leukemia

A fast-growing cancer in which too many myeloblasts (a type of immature white blood cell) are found in the bone marrow and…

Adenocarcinoma

Cancer that forms in the glandular tissue, which lines certain internal organs and makes and releases substances in the body, such as…

Adjuvant therapy

Additional cancer treatment given after the primary treatment to lower the risk that the cancer will come back. Adjuvant therapy may include…

Advance directive

A legal document that states a person’s wishes about receiving medical care if that person is no longer able to make medical…

Advanced cancer

A term that is often used to describe cancer that is unlikely to be cured. However, some advanced cancers can be controlled…

Adverse effect

An undesired effect of a drug or other type of treatment, such as surgery. Adverse effects can range from mild to severe…

Aggressive

In medicine, describes a tumor or disease that forms, grows, or spreads quickly. It may also describe treatment that is more severe…

Alkylating agent

A type of drug that is used in the treatment of cancer. It interferes with the cell's DNA and inhibits cancer cell…

Allogeneic stem cell transplant

A procedure in which a patient receives healthy blood-forming cells (stem cells) from a donor to replace their own stem cells that…

Alopecia

The lack or loss of hair from areas of the body where hair is usually found. Alopecia can be a side effect…

Alpha-fetoprotein

A protein normally produced by a fetus. Alpha-fetoprotein levels are usually undetectable in the blood of healthy adult men or women (who…

Amyloidosis

A group of diseases in which protein builds up in certain organs (localized amyloidosis) or throughout the body (systemic amyloidosis). Amyloidosis may…

Anal cancer

Cancer that forms in tissues of the anus. The anus is the opening of the rectum (last part of the large intestine)…

Anastrozole

A drug used to treat certain types of breast cancer in postmenopausal women. It is also being studied in the treatment of…

Anemia

A condition in which the number of red blood cells is below normal.

Anorexia

An abnormal loss of the appetite for food. Anorexia can be caused by cancer, AIDS, a mental disorder (i.e., anorexia nervosa), or…

Anthracycline

A type of antibiotic that comes from certain types of Streptomyces bacteria. Anthracyclines are used to treat many types of cancer. Anthracyclines…

Antibody-drug conjugate

A substance made up of a monoclonal antibody chemically linked to a drug. The monoclonal antibody binds to specific proteins or receptors…

Anticipatory nausea and vomiting

Nausea and vomiting that may occur before a chemotherapy treatment session begins in a patient who has had chemotherapy before. Anticipatory nausea…

Anticoagulant

A substance that is used to prevent and treat blood clots in blood vessels and the heart. Also called blood thinner.

Antiemetic

A drug that prevents or reduces nausea and vomiting.

Antimetabolite

A drug that is very similar to natural chemicals in a normal biochemical reaction in cells but different enough to interfere with…

Anxiety

Feelings of fear, dread, and uneasiness that may occur as a reaction to stress. A person with anxiety may sweat, feel restless…

Aplastic anemia

A condition in which the bone marrow is unable to produce blood cells.

Aromatase inhibitor

A drug that blocks the activity of an enzyme called aromatase, which the body uses to make estrogen in the ovaries and…

Ascites

Abnormal buildup of fluid in the abdomen that may cause swelling. In late-stage cancer, tumor cells may be found in the fluid…

Atezolizumab

A drug that binds to the protein PD-L1 to help immune cells kill cancer cells better and is used to treat different…

Atypical

Not normal. Describes a state, condition, or behavior that is unusual or different from what is considered normal. In medicine, an atypical…

Autologous stem cell transplant

A procedure in which a patient’s healthy stem cells (blood-forming cells) are collected from the blood or bone marrow before treatment, stored,…

B

B cell

A type of white blood cell that makes antibodies. B cells are part of the immune system and develop from stem cells…

Basal cell carcinoma

Cancer that begins in the lower part of the epidermis (the outer layer of the skin). It may appear as a small…

Benign

Not cancer. Benign tumors may grow larger but do not spread to other parts of the body. Also called nonmalignant.

Bereavement

A state of sadness, grief, and mourning after the loss of a loved one.

Beta-2-microglobulin

A small protein normally found on the surface of many cells, including lymphocytes, and in small amounts in the blood and urine.…

Bevacizumab

A drug that binds to the protein VEGF to help keep new blood vessels from forming and is used to treat many…

Bile duct cancer

A rare cancer that forms in the bile ducts. A bile duct is a tube that carries bile (fluid made by the…

Biological therapy

A type of treatment that uses substances made from living organisms to treat disease. These substances may occur naturally in the body…

Biomarker

A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or…

Biomarker testing

A laboratory method that uses a sample of tissue, blood, or other body fluid to check for certain genes, proteins, or other…

Biopsy

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform…

Biosimilar drug

A biological drug that is very much like another biological drug (called the reference drug) that has already been approved by the…

Bisphosphonate

A drug or substance used to treat hypercalcemia (abnormally high blood calcium) and bone pain caused by some types of cancer. Forms…

Bladder cancer

Cancer that forms in tissues of the bladder (the organ that stores urine). Most bladder cancers are transitional cell carcinomas (cancer that…

Blood

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and…

Blood chemistry study

A test done on a sample of blood to measure the amount of certain substances in the body. These substances include electrolytes…

Blood clot

A mass of blood that forms when blood platelets, proteins, and cells stick together. When a blood clot is attached to the…

Blood stem cell

An immature cell that can develop into all types of blood cells, including white blood cells, red blood cells, and platelets. Blood…

Blood transfusion

A procedure in which whole blood or parts of blood are put into a patient’s bloodstream through a vein. The blood may…

Bone marrow

The soft, spongy tissue that has many blood vessels and is found in the center of most bones. There are two types…

Bone marrow aspiration

A procedure in which a small sample of bone marrow is removed, usually from the hip bone, breastbone, or thigh bone. A…

Bone marrow biopsy

A procedure in which a small sample of bone with bone marrow inside it is removed, usually from the hip bone. A…

Bone marrow transplant

A procedure in which a patient receives healthy stem cells (blood-forming cells) to replace their own stem cells that have been destroyed…

Bone metastasis

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

Bone scan

A procedure to check for abnormal areas or damage in the bones. A very small amount of radioactive material is injected into…

Bortezomib

A drug used to treat adults with multiple myeloma or mantle cell lymphoma. It is also being studied in the treatment of…

Brachytherapy

A type of radiation therapy in which radioactive implants, such as pellets, seeds, ribbons, wires, needles, balloons, or capsules, are placed in…

Brain metastasis

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

Brain tumor

The growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (not cancer) or malignant (cancer).

Breakthrough pain

A sudden increase in pain that may occur in patients who already have chronic pain from cancer, arthritis, fibromyalgia, or other conditions.…

Breast cancer

Cancer that forms in tissues of the breast. The most common type of breast cancer is ductal carcinoma, which begins in the…

Breast density

A term used to describe the amount of dense tissue compared to the amount of fatty tissue in the breast on a…

Breast reconstruction

Surgery to rebuild the shape of the breast after a mastectomy.

Bronchoscopy

A procedure that uses a bronchoscope to examine the inside of the trachea, bronchi (air passages that lead to the lungs), and…

C

CA 19-9

A substance released into the bloodstream by both cancer cells and normal cells. Too much CA 19-9 in the blood can be…

CA-125

A substance that may be found in high amounts in the blood of patients with certain types of cancer, including ovarian cancer.…

Cachexia

A condition marked by a loss of more than 10% of body weight, including loss of muscle mass and fat, in a…

Cancer

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to…

Capecitabine

A drug used alone or with other drugs to treat certain types of colorectal cancer, breast cancer, esophageal cancer, gastroesophageal junction cancer,…

CAR T-cell therapy

A type of treatment in which a patient's T cells (a type of immune system cell) are changed in the laboratory so…

Carboplatin

A drug used to treat advanced ovarian cancer that has never been treated or has come back after treatment with other anticancer…

Carcinogen

Any substance that causes cancer.

Carcinoid tumor

A slow-growing type of tumor usually found in the gastrointestinal system (most often in the small intestine and rectum), and sometimes in…

Carcinoma

Cancer that begins in the skin or in tissues that line or cover internal organs.

Cardiotoxicity

Toxicity that affects the heart.

Caregiver

A person who gives care to people who need help taking care of themselves. Examples include children, the elderly, or patients who…

Carrier

In genetics, a person who has one copy of a mutated (changed) disease-causing gene but has no symptoms or mild symptoms. Carriers…

Catheter

A flexible tube used to deliver fluids into or withdraw fluids from the body.

CEA

A substance that may be found in the blood of people who have colon cancer, other types of cancer or diseases, or…

Cell

In biology, the smallest unit that can live on its own and that makes up all living organisms and the tissues of…

Central venous access catheter

A device used to draw blood and give treatments, including intravenous fluids, drugs, or blood transfusions. A thin, flexible tube is inserted…

Cervical cancer

Cancer that forms in tissues of the cervix (the organ connecting the uterus and vagina). It is usually a slow-growing cancer that…

Chemo brain

A term commonly used to describe thinking and memory problems that a patient with cancer may have before, during, or after cancer…

Chemoprevention

The use of certain drugs or other substances to help lower a person’s risk of developing cancer or keep it from coming…

Chemotherapy

Treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing.…

Chromosome

Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.

Chronic lymphocytic leukemia

An indolent (slow-growing) cancer in which too many immature lymphocytes (white blood cells) are found mostly in the blood and bone marrow.…

Chronic myelogenous leukemia

An indolent (slow-growing) cancer in which too many myeloblasts are found in the blood and bone marrow. Myeloblasts are a type of…

Cisplatin

A drug used alone or with other drugs to treat certain types of bladder cancer, ovarian cancer, and testicular cancer. It is…

Clinical trial

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening,…

Cognitive impairment

Problems with a person’s ability to think, learn, remember, use judgement, and make decisions. Signs of cognitive impairment include memory loss and…

Colon cancer

Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers…

Colonoscopy

Examination of the inside of the colon using a colonoscope, inserted into the rectum. A colonoscope is a thin, tube-like instrument with…

Colony-stimulating factor

A substance that stimulates the production of blood cells. Colony-stimulating factors include granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and promegapoietin.

Colorectal cancer

Cancer that develops in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the…

Colostomy

An opening into the colon from the outside of the body. A colostomy provides a new path for waste material to leave…

Combination chemotherapy

Treatment using more than one anticancer drug.

Complementary medicine

Treatments that are used along with standard treatments, but are not considered standard. Standard treatments are based on the results of scientific…

Complete blood count

A measure of the number of red blood cells, white blood cells, and platelets in the blood. The amount of hemoglobin (substance…

Complete remission

The disappearance of all signs of cancer in response to treatment. This does not always mean the cancer has been cured. Also…

Complete response

The disappearance of all signs of cancer in response to treatment. This does not always mean the cancer has been cured. Also…

Constipation

A condition in which stool becomes hard, dry, and difficult to pass, and bowel movements don’t happen very often. Other symptoms may…

Control group

In a clinical trial, the group that does not receive the new treatment being studied. This group is compared to the group…

Copay

The amount of money that a patient with health insurance pays for each health care service, such as a visit to the…

Core biopsy

The removal of a tissue sample with a wide needle for examination under a microscope. Also called core needle biopsy.

Corticosteroid

Any steroid hormone made in the adrenal cortex (the outer part of the adrenal gland). They are also made in the laboratory.…

Counseling

The process by which a professional counselor helps a person cope with mental or emotional distress, and understand and solve personal problems.

CT scan

A procedure that uses a computer linked to an x-ray machine to make a series of detailed pictures of areas inside the…

Cyclophosphamide

A drug used to treat many types of cancer and a certain type of kidney disease in children. Cyclophosphamide damages the cell’s…

Cyst

A closed, sac-like pocket of tissue that can form anywhere in the body. It may be filled with fluid, air, pus, or…

Cytogenetic analysis

The process of analyzing cells in a sample of tissue, blood, bone marrow, or amniotic fluid to look for changes in chromosomes,…

Cytology

The study of cells using a microscope.

Cytopenia

A condition in which there is a lower-than-normal number of blood cells.

D

Daratumumab

A drug used alone or with other drugs to treat adults with multiple myeloma. It is used in patients whose cancer is…

Deductible

The amount of money that a patient with health insurance pays for health care services before the health insurance plan begins to…

Deep vein thrombosis

The formation of a blood clot in a deep vein of the leg or lower pelvis. Symptoms may include pain, swelling, warmth,…

Dehydration

A condition that occurs when the body loses too much water and other fluids that it needs to work normally. Dehydration is…

Denosumab

A drug used to prevent or treat certain bone problems. Denosumab is used under the brand name Xgeva to prevent bone problems…

Depression

A mental condition marked by ongoing feelings of sadness, despair, loss of energy, and difficulty dealing with normal daily life. Other symptoms…

Dexamethasone

A drug used to reduce inflammation and lower the body’s immune response. It is used with other drugs to treat leukemia, lymphoma,…

Diagnosis

The process of identifying a disease, condition, or injury from its signs and symptoms. A health history, physical exam, and tests, such…

Diagnostic mammogram

An x-ray picture of the breast used to check for breast cancer after a lump or other sign or symptom of the…

Diarrhea

Frequent or uncontrollable bowel movements that may be soft, loose, or watery. Other symptoms of diarrhea include stomach pain or cramps, excessive…

Dietitian

A health professional who has special training in diet and nutrition. Dietitians offer advice on nutrition and healthy eating habits to help…

Differentiation

In biology, describes the processes by which immature cells become mature cells with specific functions. In cancer, this describes how much or…

Diffuse large B-cell lymphoma

A term used to describe a group of fast-growing B-cell non-Hodgkin lymphomas (NHL) in which the cancer cells look large when viewed…

Disease-free survival

In cancer, the length of time after primary treatment for a cancer ends that the patient survives without any signs or symptoms…

Distant cancer

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

Distress

Emotional, social, spiritual, or physical pain or suffering that may cause a person to feel sad, afraid, depressed, anxious, or lonely. People…

DNA

The molecule inside cells that contains the genetic information needed for a person and most other organisms to develop and grow and…

Docetaxel

A drug used alone or with other drugs to treat certain types of breast cancer, stomach cancer, gastroesophageal junction cancer, non-small cell…

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.

Drug resistance

When cancer cells or microorganisms, such as bacteria or viruses, don’t respond to a drug that is usually able to kill or…

Ductal carcinoma in situ

A condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside…

Durvalumab

A drug that binds to the protein PD-L1 to help immune cells kill cancer cells better and is used to treat different…

Dysgeusia

A bad taste in the mouth. Also called parageusia.

Dysplasia

A term used to describe the presence of abnormal cells within a tissue or organ. Dysplasia is not cancer, but it may…

Dysplastic nevus

A specific type of nevus (mole) that looks different from a common mole. Dysplastic nevi are mostly flat and often larger than…

E

Early menopause

A condition in which the ovaries stop working and menstrual periods stop before age 40. This can cause fertility problems and symptoms…

Ecchymosis

A small bruise caused by blood leaking from broken blood vessels into the tissues of the skin or mucous membranes.

Echocardiogram

A computer picture of the heart created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs of the chest. Echocardiograms…

Edema

Swelling caused by excess fluid in body tissues.

EGFR

A protein found on certain types of cells that binds to a substance called epidermal growth factor. The EGFR protein is involved…

Eligibility criteria

In clinical trials, requirements that must be met for a person to be included in a trial. These requirements help make sure…

Embolism

A block in an artery caused by blood clots or other substances, such as fat globules, infected tissue, or cancer cells.

End-of-life care

Care given to people who are near the end of life and have stopped treatment to cure or control their disease. End-of-life…

Endometrial cancer

Cancer that forms in the tissue lining the uterus (the small, hollow, pear-shaped organ in a woman's pelvis in which a fetus…

Endoscopy

A procedure that uses an endoscope to examine the inside of the body. An endoscope is a thin, tube-like instrument with a…

Erythropoiesis-stimulating agent

A substance that stimulates the bone marrow to make more red blood cells. Erythropoiesis-stimulating agents are used to treat anemia caused by…

Esophageal cancer

Cancer that forms in tissues lining the esophagus (the muscular tube through which food passes from the throat to the stomach). Two…

Essential thrombocythemia

An increased number of thrombocytes (platelets) in the blood, without a known cause. Also called essential thrombocytosis.

Estrogen receptor

A protein found inside the cells of the female reproductive tissue, some other types of tissue, and some cancer cells. The hormone…

Excisional biopsy

A surgical procedure in which a cut is made through the skin to remove an entire lump or suspicious area so it…

Exemestane

A drug used to treat postmenopausal women with advanced breast cancer or early-stage breast cancer that is estrogen receptor positive (ER+). It…

External beam radiation therapy

A type of radiation therapy that uses a machine outside the body to send high-energy radiation beams toward the area of the…

F

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…

False-positive test result

A test result that indicates that a person has a specific disease or condition when the person actually does not have the…

Family history

A record of the relationships among family members along with their medical histories. This includes current and past illnesses. A family history…

Fatigue

An extreme sense of tiredness and lack of energy that can interfere with a person's usual daily activities. A person with fatigue…

FDA

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional…

Febrile neutropenia

A condition marked by fever and a lower-than-normal number of neutrophils in the blood. A neutrophil is a type of white blood…

Ferritin

A protein that binds to iron and stores it for use by the body. Ferritin is found in cells in the liver,…

Fertility

The ability to produce children.

Fertility preservation

A type of procedure used to help keep a person’s ability to have children. A fertility preservation procedure is done before a…

Fever

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

Financial toxicity

In medicine, a term used to describe problems a patient has related to the cost of medical care. Not having health insurance…

Fine-needle aspiration biopsy

The removal of fluid, cells, or tissue with a thin needle for examination under a microscope. Also called FNA biopsy.

First-line therapy

The first treatment given for a disease. It is often part of a standard set of treatments, such as surgery followed by…

FISH

A laboratory method used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye…

Five-year survival rate

The percentage of people in a study or treatment group who are alive five years after they were diagnosed with or started…

Flow cytometry

A laboratory method that measures the number of cells, the percentage of live cells, and certain characteristics of cells, such as size…

Fluorouracil

A drug given as an injection to treat cancers of the breast, colon, rectum, stomach, and pancreas and as a cream to…

FOLFIRI

An abbreviation for a chemotherapy combination used to treat advanced colorectal cancer that has spread. It is also being studied in the…

FOLFOX

An abbreviation for a combination chemotherapy regimen that is used to treat colorectal cancer. It includes the drugs leucovorin calcium (folinic acid),…

Folic acid

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Folic acid helps…

Follicular lymphoma

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…

Follow-up care

Care given to a patient over time after finishing treatment for a disease. Follow-up care involves regular medical checkups, which may include…

G

G-CSF

A drug used under the brand names Neupogen, Zarxio, and Nivestym to treat neutropenia (a lower-than-normal number of white blood cells), prevent…

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…

Gastrointestinal stromal tumor

A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. Some gastrointestinal stromal tumors may grow…

Gene

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the…

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…

Genetic counselor

A health professional who has special training in medical genetics and counseling. Genetic counselors help patients and families who have, or who…

Genetic testing

A laboratory method that looks for changes in genes, gene expression, or chromosomes in a person’s cells or tissues. Genetic testing may…

Germline mutation

A gene change in a body's reproductive cell (egg or sperm) that becomes incorporated into the DNA of every cell in the…

Gleason score

A way of describing prostate cancer based on how abnormal the cancer cells in a biopsy sample look under a microscope and…

Glioblastoma

A fast-growing type of central nervous system tumor that forms from glial (supportive) tissue of the brain and spinal cord and has…

Grade

In cancer, a description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how…

Granulocyte

A type of immune cell that has granules (small particles) with enzymes that are released during infections, allergic reactions, and asthma. Neutrophils,…

Growth factor

A substance made by the body that functions to regulate cell division and cell survival. Some growth factors are also produced in…

Gynecologic oncologist

A doctor who has special training in diagnosing and treating cancers of the female reproductive organs.

H

Hand-foot syndrome

A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect…

Head and neck cancer

Cancer that forms in certain areas of the head and neck, including tissues in the nasal cavity (the hollow space inside the…

Health care proxy

A type of advance directive that gives a person (called a proxy) the authority to make medical decisions for another person if…

Hematocrit

The amount of whole blood that is made up of red blood cells. It depends on the number and size of red…

Hematologic cancer

Cancer that begins in blood-forming tissue, such as the bone marrow, or in the cells of the immune system. Examples of hematologic…

Hematologist

A doctor who has special training in diagnosing and treating blood disorders.

Hemochromatosis

A condition in which the body takes up and stores more iron than it needs. The extra iron is stored in the…

Hemoglobin

A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon…

Hemophilia

Group of hereditary disorders in which affected individuals fail to make enough of certain proteins needed to form blood clots.

Heparin

A substance that slows the formation of blood clots. Heparin is made by the liver, lungs, and other tissues in the body…

Hepatocellular carcinoma

A type of cancer that forms in liver cells called hepatocytes. Hepatocytes are the most common cells of the liver, and they…

HER2

A protein involved in normal cell growth. HER2 may be made in larger than normal amounts by some types of cancer cells,…

Hereditary cancer syndrome

A type of inherited disorder in which there is a higher-than-normal risk of certain types of cancer. Hereditary cancer syndromes are caused…

Histology

The study of tissues and cells under a microscope.

Hodgkin lymphoma

A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The…

Hormone receptor

A cell protein that binds a specific hormone. The hormone receptor may be on the surface of the cell or inside the…

Hormone therapy

Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone…

Hospice

A program that gives special care to people who are near the end of life and have stopped treatment to cure or…

Hot flash

A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).

HPV

A group of more than 200 common viruses. Some HPVs, called cutaneous HPVs, are transmitted by casual contact and can infect the…

Hydroxyurea

A drug used alone or with other anticancer drugs or radiation therapy under the brand name Hydrea to treat certain types of…

Hypercalcemia

Higher than normal levels of calcium in the blood. Some types of cancer increase the risk of hypercalcemia.

Hyperplasia

An increase in the number of cells in an organ or tissue. These cells appear normal under a microscope. They are not…

I

Ibrutinib

A drug used alone or with other drugs to treat adults with chronic lymphocytic leukemia, small lymphocytic lymphoma, or Waldenstrom macroglobulinemia (a…

Imaging

In medicine, a process that makes pictures of areas inside the body. Imaging uses methods such as x-rays (high-energy radiation), ultrasound (high-energy…

Immune checkpoint inhibitor

A type of drug that blocks proteins called checkpoints that are made by some types of immune system cells, such as T…

Immune thrombocytopenia

A condition in which platelets (blood cells that cause blood clots to form) are destroyed by the immune system. The low platelet…

Immunocompromised

Having a weakened immune system. People who are immunocompromised have a reduced ability to fight infections and other diseases. This may be…

Immunohistochemistry

A laboratory method that uses antibodies to check for certain antigens (markers) in a sample of tissue. The antibodies are usually linked…

Immunosuppression

Suppression of the body's immune system and its ability to fight infections and other diseases. Immunosuppression may be deliberately induced with drugs,…

Immunotherapy

A type of therapy that uses substances to stimulate or suppress the immune system to help the body fight cancer, infection, and…

In situ

In its original place. For example, in carcinoma in situ, abnormal cells are found only in the place where they first formed.…

Incidence

The number of new cases of a disease diagnosed each year.

Incisional biopsy

A surgical procedure in which a cut is made through the skin to remove a sample of abnormal tissue or part of…

Indolent

A type of cancer that grows slowly.

Infection

The invasion and growth of germs in the body. The germs may be bacteria, viruses, yeast, fungi, or other microorganisms. Infections can…

Infertility

The inability to produce children.

Inflammatory breast cancer

A rare, fast-growing type of breast cancer in which cancer cells block lymph vessels in the skin of the breast, causing the…

Informed consent

A process in which patients are given important information, including possible risks and benefits, about a medical procedure or treatment, genetic testing,…

Infusion

A method of putting fluids, including drugs, into the bloodstream. Also called intravenous infusion.

Inherited

In medicine, describes the passing of genetic information from parent to child through the genes in sperm and egg cells. Also called…

Injection

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

Insomnia

Difficulty in going to sleep or getting enough sleep.

Integrative medicine

An approach to medical care that recognizes the benefit of combining conventional (standard) therapies (such as drugs and surgery) with complementary therapies…

Intravenous

Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or…

Invasive cancer

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called…

Invasive ductal carcinoma

The most common type of invasive breast cancer. It begins in the lining of the milk ducts (thin tubes that carry milk…

Invasive lobular carcinoma

A type of invasive breast cancer that begins in the lobules (milk glands) of the breast and spreads to surrounding normal tissue.…

Investigational drug

A substance that has been tested in the laboratory and has been approved by the U.S. Food and Drug Administration (FDA) for…

Ipilimumab

A drug that binds to the protein CTLA-4 to help immune cells kill cancer cells better and is used to treat many…

Iron overload

A condition in which the body takes up and stores more iron than it needs. The extra iron is stored in the…

K

Kidney cancer

Cancer that forms in tissues of the kidneys. There are many different types of kidney cancer, including renal cell carcinoma (RCC), transitional…

L

Lactate dehydrogenase

One of a group of enzymes found in the blood and other body tissues and involved in energy production in cells. An…

Laryngeal cancer

Cancer that forms in tissues of the larynx. The larynx is the area of the throat that contains the vocal cords and…

Late effect

A health problem that occurs months or years after a disease is diagnosed or after treatment has ended. Late effects may be…

Lenalidomide

A drug that is similar to thalidomide and is used alone or with other drugs to treat adults with certain types of…

Lesion

An area of abnormal or damaged tissue caused by injury, infection, or disease. A lesion can occur anywhere in or on the…

Letrozole

A drug used to treat certain types of breast cancer in postmenopausal women. It is also being studied in the treatment of…

Leukemia

Cancer that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of abnormal blood cells to be produced…

Leukopenia

A condition in which there is a lower-than-normal number of leukocytes (white blood cells) in the blood.

Liquid biopsy

A laboratory test done on a sample of blood, urine, or other body fluid to look for cancer cells from a tumor…

Liver cancer

Primary liver cancer is cancer that forms in the tissues of the liver. Secondary liver cancer is cancer that spreads to the…

Living will

A type of advance directive that states the specific types of medical care that a person wishes to receive if that person…

Lobular carcinoma in situ

A condition in which abnormal cells are found in the lobules of the breast. This condition seldom becomes invasive cancer. However, having…

Local therapy

Treatment that is directed to a specific organ or limited area of the body, such as the breast or an abnormal growth…

Localized

In medicine, describes disease that is limited to a certain part of the body. For example, localized cancer is usually found only…

Low-dose CT scan

A procedure that uses a computer linked to an x-ray machine that gives off a very low dose of radiation to make…

Lumpectomy

Surgery to remove cancer or other abnormal tissue from the breast and some normal tissue around it, but not the breast itself.…

Lung cancer

Cancer that forms in tissues of the lung, usually in the cells lining air passages. The two main types are small cell…

Lymph node

A small bean-shaped structure that is part of the body’s immune system. Lymph nodes filter substances that travel through the lymphatic fluid,…

Lymph node dissection

A surgical procedure in which the lymph nodes are removed and a sample of tissue is checked under a microscope for signs…

Lymphadenopathy

Disease or swelling of the lymph nodes.

Lymphatic system

The tissues and organs that help the body fight infection and disease. The lymphatic system includes the lymph nodes, lymph vessels (thin…

Lymphedema

A condition in which lymph builds up in tissues and causes swelling. Lymphedema usually affects an arm or leg, but it can…

Lymphocyte

A type of immune cell that is made in the bone marrow and is found in the blood and in lymph tissue.…

Lymphoma

Cancer that begins in cells of the immune system. There are two basic categories of lymphomas. One kind is Hodgkin lymphoma, which…

Lynch syndrome

An inherited disorder that increases the risk of developing colorectal cancer, endometrial cancer, ovarian cancer, and many other types of cancer, such…

M

M protein

An antibody found in unusually large amounts in the blood or urine of people with multiple myeloma and other types of plasma…

Maintenance therapy

Treatment that is given to help keep cancer from coming back after it has disappeared following the initial therapy. It may include…

Malignant

A term used to describe cancer. Malignant cells grow in an uncontrolled way and can invade nearby tissues and spread to other…

Mammogram

An x-ray image of the breast used to detect signs of breast cancer or other abnormal breast changes. It is used both…

Mantle cell lymphoma

An aggressive (fast-growing) type of B-cell non-Hodgkin lymphoma that usually occurs in middle-aged or older adults. It is marked by small- to…

Margin

The edge or border of the tissue removed in cancer surgery. The margin is described as negative or clean when the pathologist…

Mass

In medicine, a lump in the body. It may be caused by the abnormal growth of cells, a cyst, hormonal changes, or…

Mastectomy

Surgery to remove part or all of the breast. There are different types of mastectomy that differ in the amount of tissue…

Medical oncologist

A doctor who has special training in diagnosing and treating cancer in adults using chemotherapy, hormonal therapy, biological therapy, and targeted therapy.…

Melanoma

A form of cancer that begins in melanocytes (cells that make the pigment melanin). It may begin in a mole (skin melanoma),…

Meningioma

A type of slow-growing tumor that forms in the meninges (thin layers of tissue that cover and protect the brain and spinal…

Merkel cell carcinoma

A rare type of cancer that forms on or just beneath the skin, usually in parts of the body that have been…

Mesothelioma

A benign (not cancer) or malignant (cancer) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the…

Metastasis

The spread of cancer cells from the place where they first formed to another part of the body. In metastasis, cancer cells…

Metastasize

To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the…

Metastatic

Having to do with metastasis, which is the spread of cancer from the primary site (place where it started) to other places…

Microsatellite instability

A change that occurs in certain cells (such as cancer cells) in which the number of repeated DNA bases in a microsatellite…

Mole

A benign (not cancer) growth on the skin that is formed by a cluster of melanocytes (cells that make a substance called…

Monoclonal antibody

A type of protein that is made in the laboratory and can bind to certain targets in the body, such as antigens…

Monoclonal gammopathy of undetermined significance

A benign condition in which there is a higher-than-normal level of a protein called M protein in the blood. Patients with monoclonal…

Monocyte

A type of immune cell that is made in the bone marrow and travels through the blood to tissues in the body…

MRI

A procedure that uses radio waves, a powerful magnet, and a computer to make a series of detailed pictures of areas inside…

Mucositis

A complication of some cancer therapies in which the lining of the digestive system becomes inflamed. Often seen as sores in the…

Multidisciplinary

In medicine, a term used to describe a treatment planning approach or team that includes a number of doctors and other health…

Multiple myeloma

A type of cancer that begins in plasma cells (white blood cells that produce antibodies). Also called Kahler disease, myelomatosis, and plasma…

Mutation

Any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be…

Myelodysplastic syndrome

A type of cancer in which the bone marrow does not make enough healthy blood cells (white blood cells, red blood cells,…

Myelofibrosis

A disorder in which the bone marrow is replaced by fibrous tissue.

Myeloma

Cancer that arises in plasma cells, a type of white blood cell.

Myeloproliferative neoplasm

A type of disease in which the bone marrow makes too many red blood cells, platelets, or certain white blood cells. Myeloproliferative…

Myelosuppression

A condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets. Myelosuppression is…

N

Nausea

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect…

Needle biopsy

The removal of tissue or fluid with a needle for examination under a microscope. When a wide needle is used, the procedure…

Neoadjuvant therapy

Treatment given as a first step to shrink a tumor before the main treatment, which is usually surgery, is given. Examples of…

Neoplasm

An abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they…

Neuroendocrine tumor

A tumor that forms from cells that release hormones into the blood in response to a signal from the nervous system. Neuroendocrine…

Neuropathy

A nerve problem that causes pain, numbness, tingling, swelling, or muscle weakness in different parts of the body. It usually begins in…

Neutropenia

A condition in which there is a lower-than-normal number of neutrophils (a type of white blood cell) in the blood.

Neutrophil

A type of white blood cell that is an important part of the immune system and helps the body fight infection. When…

Next-generation sequencing

A term that describes methods used in the lab to learn the order of building blocks (called nucleotides) for millions of DNA…

Night sweats

Episodes of excessive sweating that occur during sleep. Night sweats can be severe and soak a person’s bedclothes and bed sheets, which…

Nivolumab

A drug that binds to the protein PD-1 to help immune cells kill cancer cells better and is used to treat many…

Nodule

A growth or lump that may be malignant (cancer) or benign (not cancer).

Non-Hodgkin lymphoma

Any of a large group of cancers of lymphocytes (white blood cells). Non-Hodgkin lymphomas can occur at any age and are often…

Non-small cell lung cancer

A group of lung cancers named for the kinds of cells found in the cancer and how the cells look under a…

Nurse practitioner

A registered nurse who has additional education and training in how to diagnose and treat disease. Nurse practitioners are licensed at the…

Nutrition

The taking in and use of food and other nourishing material by the body. Nutrition is a 3-part process. First, food or…

O

Off-label

Describes the legal use of a prescription drug to treat a disease or condition for which the drug has not been approved…

Oncologist

A doctor who has special training in diagnosing and treating cancer. Some oncologists specialize in a particular type of cancer treatment. For…

Oncology nurse

A nurse who specializes in treating and caring for people who have cancer.

Oral

By or having to do with the mouth.

Oropharyngeal cancer

Cancer that forms in tissues of the oropharynx (the middle part of the throat, behind the mouth). The oropharynx includes the soft…

Osteosarcoma

A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young…

Outcome

A specific result or effect that can be measured. Examples of outcomes include decreased pain, reduced tumor size, and improvement of disease.

Ovarian cancer

Cancer that forms in tissues of the ovary (one of a pair of female reproductive glands in which the ova, or eggs,…

Overall survival

The length of time from either the date of diagnosis or the start of treatment for a disease, such as cancer, that…

Oxaliplatin

A drug used with other drugs to treat stage III colon cancer that was removed by surgery and colorectal cancer that is…

P

Paclitaxel

A drug used alone or with other drugs to treat AIDS-related Kaposi sarcoma, advanced ovarian cancer, and certain types of breast cancer…

Paget disease of the breast

A rare type of breast cancer that involves the nipple and, usually, the areola (the darker circle of skin around the nipple).…

Palliative care

Care given to improve the quality of life and help reduce pain in people who have a serious or life-threatening disease, such…

Pancreatic cancer

Cancer that forms in the tissues of the pancreas. The pancreas is an organ in the abdomen that helps the body digest…

Pancytopenia

A condition in which there is a lower-than-normal number of red and white blood cells and platelets in the blood. Pancytopenia occurs…

Pap test

A procedure in which a small brush is used to gently remove cells from the surface of the cervix and the area…

Paracentesis

A procedure in which a thin needle or tube is put into the abdomen to remove fluid from the peritoneal cavity (the…

PARP inhibitor

A substance that blocks an enzyme in cells called PARP. PARP helps repair DNA when it becomes damaged. DNA damage may be…

Partial remission

A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment. Also…

Partial response

A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment. Also…

Pathologist

A doctor who has special training in identifying diseases by studying cells and tissues under a microscope.

Pathology report

The description of cells and tissues made by a pathologist based on microscopic evidence, and sometimes used to make a diagnosis of…

Patient advocate

A person who helps guide a patient through the health care system. This includes help going through the screening, diagnosis, treatment, and…

Patient navigator

A person who helps guide a patient through the health care system. This includes help going through the screening, diagnosis, treatment, and…

PD-L1

A protein that acts as a kind of “brake” to keep the body’s immune responses under control. PD-L1 may be found on…

Pembrolizumab

A drug that binds to the protein PD-1 to help immune cells kill cancer cells better and is used to treat many…

Penile cancer

A rare cancer that forms in the penis (an external male reproductive organ). Most penile cancers are squamous cell carcinomas (cancer that…

Peripheral blood smear

A procedure in which a sample of blood is viewed under a microscope to count different circulating blood cells (red blood cells,…

Peripheral neuropathy

A nerve problem that causes pain, numbness, tingling, swelling, or muscle weakness in different parts of the body. It usually begins in…

Pernicious anemia

A condition in which the body is unable to properly absorb vitamin B12, leading to a lower-than-normal number of red blood cells…

Pertuzumab

A drug used with other drugs to treat breast cancer that is HER2 positive. It is used in patients whose cancer has…

PET scan

A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to…

PET-CT scan

A procedure that combines the pictures from a positron emission tomography (PET) scan and a computed tomography (CT) scan. The PET and…

Petechiae

Pinpoint, unraised, round red spots under the skin caused by bleeding.

Phase I clinical trial

The first step in testing a new treatment in humans. A phase I clinical trial tests the safety, side effects, best dose,…

Phase II clinical trial

A study that tests whether a new treatment works for a certain type of cancer or other disease (for example, whether it…

Phase III clinical trial

A study that tests the safety and how well a new treatment works compared with a standard treatment. For example, phase III…

Phase IV clinical trial

A type of clinical trial that studies the side effects caused over time by a new treatment after it has been approved…

Phlebotomy

A procedure in which a needle is used to take blood from a vein, usually for laboratory testing. Phlebotomy may also be…

Physical therapy

The use of exercises and physical activities to help condition muscles and restore strength and movement. For example, physical therapy can be…

Physician assistant

A health professional who is licensed to do certain medical procedures under the guidance of a doctor. A physician assistant may take…

PICC

A device used to draw blood and give treatments, including intravenous fluids, drugs, or blood transfusions. A thin, flexible tube is inserted…

Placebo

An inactive substance or other intervention that looks the same as, and is given the same way as, an active drug or…

Plasma

The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.

Plasma cell

A type of immune cell that makes large amounts of a specific antibody. Plasma cells develop from B cells that have been…

Platelet

A tiny, disc-shaped piece of cell that is found in the blood and spleen. Platelets are pieces of very large cells in…

Pleural effusion

An abnormal collection of fluid between the thin layers of tissue (pleura) lining the lung and the wall of the chest cavity.

Polycythemia vera

A disease in which there are too many red blood cells in the bone marrow and blood, causing the blood to thicken.…

Polyp

A growth that protrudes from a mucous membrane.

Port

A device used to draw blood and give treatments, including intravenous fluids, blood transfusions, or drugs such as chemotherapy and antibiotics. The…

Precancerous

A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

Prevention

In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors…

Primary tumor

A term used to describe the original, or first, tumor in the body. Cancer cells from a primary tumor may spread to…

Principal investigator

The person(s) in charge of a clinical trial or a scientific research grant. The principal investigator prepares and carries out the clinical…

Progesterone receptor

A protein found inside the cells of the female reproductive tissue, some other types of tissue, and some cancer cells. The hormone…

Prognosis

The likely outcome or course of a disease; the chance of recovery or recurrence.

Progression

In medicine, the course of a disease, such as cancer, as it becomes worse or spreads in the body.

Progression-free survival

The length of time during and after the treatment of a disease, such as cancer, that a patient lives with the disease…

Prostate cancer

Cancer that forms in the tissues of the prostate (a gland in the male reproductive system that lies just below the bladder…

Protocol

A detailed plan of a scientific or medical experiment, treatment, or procedure. In clinical trials, it states what the study will do,…

PSA

A protein made by the prostate gland and found in the blood. PSA blood levels may be higher than normal in men…

PSA test

A laboratory test that measures the amount of prostate-specific antigen (PSA) found in the blood. PSA is a protein made by the…

Pulmonary embolism

A sudden blockage of an artery (blood vessel) in the lung. A pulmonary embolism usually occurs when a blood clot in a…

Q

Quality of life

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These…

R

Radiation oncologist

A doctor who has special training in using radiation to treat cancer.

Radiation therapy

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation…

Radiologist

A doctor who has special training in creating and interpreting pictures of areas inside the body. The pictures are made with x-rays,…

Randomized clinical trial

A study in which the participants are divided by chance into separate groups that compare different treatments or other interventions. Using chance…

Rash

An area of the skin that has changes in texture or color and may look inflamed or irritated. The skin may be…

Rectal cancer

Cancer that forms in the tissues of the rectum (the last several inches of the large intestine closest to the anus).

Recurrence

Cancer that has recurred (come back), usually after a period of time during which the cancer could not be detected. The cancer…

Recurrent cancer

Cancer that has recurred (come back), usually after a period of time during which the cancer could not be detected. The cancer…

Red blood cell

A type of blood cell that is made in the bone marrow and found in the blood. Red blood cells contain a…

Referral

In medicine, the act of sending a patient from one health care provider to another for additional health care services. For example,…

Refractory

In medicine, describes a disease or condition that does not respond to treatment.

Regimen

A treatment plan that specifies the dosage, the schedule, and the duration of treatment.

Regional cancer

Refers to cancer that has grown beyond the original (primary) tumor to nearby lymph nodes or organs and tissues.

Registered dietitian

A health professional who has special training in diet and nutrition. Registered dietitians offer advice on nutrition and healthy eating habits to…

Rehabilitation

In medicine, a process to restore mental and/or physical abilities lost to injury or disease, in order to function in a normal…

Relapse

The return of a disease or the signs and symptoms of a disease after a period of improvement. Relapse also refers to…

Remission

A decrease in or disappearance of signs and symptoms of cancer. In partial remission, some, but not all, signs and symptoms of…

Renal cell cancer

Cancer that begins in the lining of the tiny tubes in the kidney that return filtered substances that the body needs back…

Response

In medicine, an improvement related to treatment.

Response rate

The percentage of patients whose cancer shrinks or disappears after treatment.

Restaging

A process used to find out the amount or spread of cancer in the body if it comes back or gets worse…

Risk factor

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of…

Rituximab

A drug used alone or with other drugs under the brand names Riabni, Rituxan, Ruxience, and Truxima to treat certain types of…

S

Sarcoma

A type of cancer that begins in bone or in the soft tissues of the body, including cartilage, fat, muscle, blood vessels,…

Screening

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better…

Screening mammogram

An x-ray image of the breast used to check for breast cancer in people who have no signs or symptoms of the…

Second opinion

In medicine, the opinion of a doctor other than the patient’s current doctor. The second doctor reviews the patient’s medical records and…

Second-line therapy

Treatment that is given when initial treatment (first-line therapy) doesn’t work, or stops working.

Sentinel lymph node

The first lymph node to which cancer is likely to spread from the primary tumor. When cancer spreads, the cancer cells may…

Sentinel lymph node biopsy

Removal and examination of the sentinel node(s) (the first lymph node(s) to which cancer cells are likely to spread from a primary…

Serum

The clear liquid part of the blood that remains after blood cells and clotting proteins have been removed.

Sickle cell anemia

An inherited disease in which the red blood cells have an abnormal crescent shape, block small blood vessels, and do not last…

Sickle cell disease

An inherited disease in which the red blood cells have an abnormal crescent shape, block small blood vessels, and do not last…

Side effect

An effect of a drug or other type of treatment that is in addition to or beyond its desired effect. Side effects…

Skin cancer

Cancer that forms in the tissues of the skin. There are several types of skin cancer. Skin cancer that forms in melanocytes…

Small cell lung cancer

An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body. The cancer…

Smoldering myeloma

A very slow-growing type of myeloma in which abnormal plasma cells (a type of white blood cell) make too much of a…

Social worker

A professional trained to talk with people and their families about emotional or physical needs, and to find them support services.

Soft tissue sarcoma

A cancer that begins in the muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

Solid tumor

An abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancer), or…

Somatic mutation

An alteration in DNA that occurs after conception. Somatic mutations can occur in any of the cells of the body except the…

Spleen

An organ that is part of the lymphatic and blood systems. The spleen filters the blood to help destroy microorganisms and get…

Splenomegaly

Enlarged spleen.

Squamous cell carcinoma

Cancer that begins in squamous cells. Squamous cells are thin, flat cells that look like fish scales, and are found in the…

Squamous cell carcinoma of the skin

Cancer that begins in cells that form the epidermis (outer layer of the skin). It usually occurs on areas of the skin…

Stable disease

Cancer that is neither decreasing nor increasing in extent or severity.

Stage

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain…

Staging

Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from where…

Standard of care

Treatment that is accepted by medical experts as a proper treatment for a certain type of disease and that is widely used…

Stem cell

A cell from which other types of cells develop. For example, blood cells develop from blood-forming stem cells.

Stem cell transplant

A procedure in which a patient receives healthy stem cells (blood-forming cells) to replace their own stem cells that have been destroyed…

Stereotactic radiosurgery

A type of external radiation therapy that uses special equipment to position the patient and precisely give a single large dose of…

Steroid

Any of a group of lipids (fats) that have a certain chemical structure. Steroids occur naturally in plants and animals or they…

Stomach cancer

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

Subcutaneous

Beneath the skin.

Support group

A group of people with similar disease or concerns who help each other cope by sharing experiences and information.

Supportive care

Care given to improve the quality of life of people who have an illness or disease by preventing or treating, as early…

Surgery

A procedure to remove or repair a part of the body or to find out whether disease is present. Also called operation.

Surgical oncologist

A surgeon who has special training in performing biopsies and other surgical procedures in cancer patients.

Survival rate

The percentage of people in a study or treatment group who are still alive for a certain period of time after they…

Survivor

One who remains alive and continues to function during and after overcoming a serious hardship or life-threatening disease. In cancer, a person…

Survivorship

In cancer, survivorship focuses on the health and well-being of a person with cancer from the time of diagnosis until the end…

Survivorship care plan

A detailed plan given to a patient after treatment ends, that contains a summary of the patient’s treatment, along with recommendations for…

Systemic therapy

Treatment using substances that travel through the bloodstream, reaching and affecting cells all over the body.

T

T cell

A type of white blood cell. T cells are part of the immune system and develop from stem cells in the bone…

Targeted therapy

A type of treatment that uses drugs or other substances to target specific molecules that cancer cells need to survive and spread.…

Taxane

A type of drug that blocks cell growth by stopping mitosis (cell division). Taxanes interfere with microtubules (cellular structures that help move…

Telehealth

The delivery of health care from a distance using electronic information and technology, such as computers, cameras, videoconferencing, satellites, wireless communications, and…

Testicular cancer

Cancer that forms in tissues of one or both testicles. Testicular cancer is most common in young or middle-aged men. Most testicular…

Thoracentesis

Removal of fluid from the pleural cavity through a needle inserted between the ribs.

Thrombocytopenia

A condition in which there is a lower-than-normal number of platelets in the blood. It may result in easy bruising and excessive…

Thrombosis

The formation or presence of a thrombus (blood clot) inside a blood vessel.

Thyroid cancer

Cancer that forms in the thyroid gland (an organ at the base of the throat that makes hormones that help control heart…

TNM staging system

A system to describe the amount and spread of cancer in a patient’s body, using TNM. T describes the size of the…

Toxicity

The extent to which something is poisonous or harmful.

Transfusion

A procedure in which whole blood or parts of blood are put into a patient’s bloodstream through a vein. The blood may…

Trastuzumab

A drug used alone or with other drugs to treat certain types of breast cancer, stomach cancer, and gastroesophageal junction cancer that…

Treatment plan

A detailed plan with information about a patient’s disease, the goal of treatment, the treatment options for the disease and possible side…

Triple-negative breast cancer

A type of breast cancer in which the tumor cells do not have estrogen receptors, progesterone receptors, or large amounts of HER2/neu…

Tumor

An abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they…

Tumor burden

Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called…

Tumor grade

A description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the…

Tumor lysis syndrome

A condition that can occur after treatment of a fast-growing cancer, especially certain leukemias and lymphomas (cancers of the blood). As tumor…

Tumor marker

A substance found in tissue, blood, bone marrow, or other body fluids that may be a sign of cancer or certain benign…

Tumor mutational burden

The total number of mutations (changes) found in the DNA of cancer cells. Knowing the tumor mutational burden may help plan the…

Tyrosine kinase inhibitor

A substance that blocks the action of enzymes called tyrosine kinases. Tyrosine kinases are a part of many cell functions, including cell…

U

Ultrasound

A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that…

Undifferentiated

A term used to describe cells or tissues that do not have specialized ("mature") structures or functions. Undifferentiated cancer cells often grow…

Urologist

A doctor who has special training in diagnosing and treating diseases of the urinary organs in females and the urinary and reproductive…

Uterine cancer

Cancer that forms in tissues of the uterus (the small, hollow, pear-shaped organ in a woman's pelvis in which a fetus develops).…

V

Vitamin B12

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Vitamin B12 helps…

Vomiting

The forceful ejection of some or all of the contents of the stomach through the mouth. Vomiting may be caused by many…

Vulvar cancer

Cancer of the vulva (the external female genital organs, including the clitoris, vaginal lips, and the opening to the vagina).

W

Waldenström macroglobulinemia

An indolent (slow-growing) type of non-Hodgkin lymphoma marked by abnormal levels of IgM antibodies in the blood and an enlarged liver, spleen,…

Warfarin

A drug that prevents blood from clotting. It belongs to the family of drugs called anticoagulants (blood thinners).

Watchful waiting

Closely watching a patient’s condition but not giving any treatment unless signs or symptoms appear or change. Watchful waiting may be used…

WBC

A type of blood cell that is made in the bone marrow and found in the blood and lymph tissue. WBCs are…

Well-differentiated

A term used to describe cells and tissue that have mature (specialized) structures and functions. In cancer, well-differentiated cancer cells look more…

White blood cell

A type of blood cell that is made in the bone marrow and found in the blood and lymph tissue. White blood…

X

X-ray

A type of radiation used in the diagnosis and treatment of cancer and other diseases. In low doses, x-rays are used to…

Xerostomia

Dry mouth. It occurs when the body is not able to make enough saliva.