Glossary of Cancer Terms

We know that during each appointment there may be several questions and concerns depending on how treatment is going. To make your cancer journey a little easier, we’ve outlined some key cancer terms you can familiarize yourself with to be more knowledgeable when coming to your next appointment. Please see below for a full list of cancer terms. To download this list, please click here.


Ablative Therapy – Treatment that removes or destroys the function of an organ. For example, removing the ovaries or having some types of chemotherapy that cause them to stop working.

Acute – Sudden onset of symptoms or disease.

Adenocarcinoma – Cancer that starts in the glandular tissue, such as in ducts or lobules of the breast.

Adenoma – A benign or malignant tumor made up of glandular tissue.

Adjuvant Chemotherapy – Chemotherapy used along with surgery or radiation therapy.

Adjuvant Therapy – Given after primary treatment to increase chances of a cure; includes chemotherapy, radiation therapy and hormone therapy.

Adrenal Gland – Glands located near the kidneys that produce hormones which control metabolism, fluid balance, and blood pressure. They also produce small amounts of ‘male’ hormones (androgens) and ‘female’ hormones (estrogens and progesterone).

Alopecia – Loss of hair. This can include all body hair besides scalp hair and can result from disease as well as certain type of cancer treatments.

Alternative Medicine – Practices not generally recognized by the medical community as standard or conventional medical approaches and used instead of standard treatments.

Alternative Therapy – Use of an unapproved therapy instead of standard (proven) therapy. The American Cancer Society recommends that patients considering the use of any alternative or complementary therapy discuss this with their healthcare professional.

Analgesic – A drug that relieves pain.

Androgen – A male hormone.

Anemia – A less than normal amount of red blood cells.

Anglogenesis – Growth of blood vessels to a solid tumor.

Antibodies – A protein formed in response to an antigen that produces immunity against certain microorganisms or toxins.

Antibody – A type of protein made by certain white blood cells in response to a foreign substance (antigen).

Antibiotic – Drugs used to kill organisms that cause disease. Antibiotics may be made by living organisms or they may be created in the lab. Since some cancer treatments can reduce the body’s ability to fight off infection, antibiotics may be used to treat or prevent these infections.

Antiemetic – A drug that prevents or controls nausea and vomiting.

Antiestrogen – A substance that blocks the effects of estrogen on tumors. Antiestrogens are used to treat breast cancers that depend on estrogen for growth.

Antifungal – A drug used to treat fungal infections.

Antigen – A substance that causes the body’s immune system to react. This reaction often involves the production of antibodies. For example, the immune system’s response to antigens that are part of bacteria and viruses helps people resist infections. Cancer cells have certain antigens that can be found by laboratory tests; they are important in cancer diagnosis and in watching response to treatment. Other cancer cells antigens play a role in immune reactions that may help the body’s resistance against cancer.

Antineoplastic – A drug that prevents, kills or blocks the growth or spread of cancer cells.

Antioxidants – Agents that help prevent cancer by reducing oxidative stress and damage to DNA caused by oxygen radicals in the body.

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

Apoptosis – The process of natural cell death that eliminates injured or genetically damaged cells.

Arrhythmia – An irregular heartbeat.

Ascites – An abnormal collection of fluid in the abdomen from cancer or other causes.

Aspiration – The removal of fluid or tissue from a specific area of the body.

Asymptomatic – Not having any symptoms of a disease.

Atypical – Not usual or abnormal.

Autoimmunity – A condition in which the body’s immune system fights its own tissues.

Axilla – The armpit.

Axillary Dissection – Removal of the lymph nodes in the armpit (axillary nodes) for examination for the presence of cancer.


Barium Enema – A study of the colon (large intestine) in which the patient is given an enema of a liquid barium mixture before the x-ray is taken.

Basal Cell Carcinoma – The most common type of skin cancer that grows slowly and is almost always curable.

Benign – A tumor that does not grow into surrounding tissue or spread to other parts of the body.

Bilateral – Occurring on both sides of the body.

Bioactive – Affecting a living organism.

Biological Response Modifiers – A substance that fights cancer by stimulating the immune system.

Biopsy – The surgical removal of a small piece of tissue for microscopic examination to determine if cancer cells are present.

Blood Cells – The red and white cells and platelets produced in the bone marrow that make up blood.

Blood Count – The number of both white and red blood cells and platelets as determined by examination of blood under a microscope.

Bolus – A single dose of drug usually injected into a blood vessel over a short period of time.

Bone Marrow – The soft spongy substance found inside bones that produces blood cells.

Bone Marrow Biopsy – A procedure in which a needle is inserted into a bone to take out a sample of bone marrow.

Bone Marrow Transplant – The addition of a donor’s bone marrow into a patient whose own bone marrow can no longer make normal blood cells.

Bone Scan – A picture of all the bones in the body taken about two hours after the injection of a radioactive dye.

Bone (skeletal) Survey – An X-ray of all the bones of the body; often done when looking for metastasis to the bones.

Brachytherapy – Internal radiation treatment given by placing radioactive material directly into the tumor or close to it.

Brain Scan – A picture of the brain taken after the injection of a radioactive dye.

Breakthrough Pain – Intense increases in pain that occur with rapid onset even when pain control medication is being used.

Breast Augmentation – Surgery to increase the size of the breast.

Breast Cancer – Cancer that starts in the tissue of the breast.

Breast Conservation Therapy – Surgery to remove breast cancer and a small amount of benign tissue around the cancer, without removing any other part of the breast. The lymph nodes under the arm may be removed, and radiation therapy is also often given after the surgery. This method is also called lumpectomy, segmental excision, limited breast surgery or tylectomy.

Breast Implant – A sac used to increase breast size or restore the contour of a breast after mastectomy. The sac is filled with silicone gel (a synthetic material) or sterile saltwater (saline).

Breast Reconstruction – Surgery that rebuilds the breast contour after mastectomy. A breast implant or the women’s own tissue is used. If desired, the nipple and areola may also be re-created. Reconstruction can be done at the time of mastectomy or any time later.

Breast Self-Exam (BSE) – A method of checking one’s own breasts for lumps or suspicious changes.

Bronchi – in the lungs, the two main air passages leading from the windpipe (trachea). The bronchi provide a passage for air to move in and out of the lungs.

Bronchoscopy – The insertion of a flexible, lighted tube through the mouth and into the lungs allowing the physician to examine and take a biopsy of the lungs and bronchi (breathing tubes).


Cancer – A general term for a large group of diseases in which there is uncontrolled growth and spread of abnormal cells.

Cancer Care Team – the group of health care professionals who work together to find, treat, and care for people with cancer. The cancer care team may include any or all of the following and others: primary care physician, pathologist, oncology specialists (medical oncologist, radiation oncologist), surgeons (including surgical specialists such as urologists, gynecologists, neurosurgeons, etc.), nurses, oncology nurse specialists, oncology social workers.

Cancer Cell – A cell that divides and reproduces abnormally and has the potential to spread throughout the body, crowding out normal cells and tissue.

Cancer Survivor – Anyone living with a history of cancer including newly diagnosed survivors as well as long-term survivors.

Candidiasis – A common fungal infection often seen as white patches on the tongue or the inside of the mouth.

Carcinogen – A substance that causes cancer.

Carcinoma – A malignant tumor that begins in the lining layer (epithelial cells) of organs.

Carcinoma in situ – The earliest stage of cancer, in which the tumor is still confined to the local area.

Cardiomyopathy – Disease of the heart muscle.

Computerized Tomography (CT) Scan – Using a machine that takes pictures of cross sections of the body, a CT Scan can show the anatomy of the brain and other parts of your body that can not be seen by regular x-ray.

Cell – The structural and functional unit of which all living things are made.

Cervical Lymph Nodes – Lymph nodes in the neck.

Cervix – The neck of the uterus.

Chemotherapy – The treatment of cancer with drugs.

Chromosome – Part of a cell that contains genetic information.

Chronic – Persisting over a long period of time.

Clinical Trial – A planned scientific study of the effects of a diagnostic test or treatment on selected patients, usually with respect to safety, efficacy, and/or quality of life.

Colon – The part of the large intestine that extends from the small intestine to the rectum.

Colonoscopy – A procedure to look at the rectum and the colon by means of a lighted, flexible tube.

Colostomy – A surgical procedure by which an opening is created between the colon and the outside of the abdomen in order to eliminate stool into a collection bag.

Combination Therapy – The use of more than one drug during cancer treatments.

Combined Modality Therapy – Treatment with two or more types of therapy – a surgery, radiotherapy, chemotherapy or biotherapy.

Complementary Therapy – Therapies used in addition to standard therapy which may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient’s sense of well being. The American Cancer Society recommends that patients considering use of any alternative or complementary therapy discuss this with their healthcare team.

Complete remission/complete response (CR) – The disappearance of all signs of cancer in response to treatment.

Consent – A patient’s oral and written agreement to a procedure or a treatment based on full disclosure about the treatment, its potential risks and benefits, alternative treatments, and any other information the patient needs to make the decision.

Corticosteroid – Any of a number of steroid substances obtained from the cortex of the adrenal glands. They are sometimes used as an anti-cancer treatment or to reduce persistent nausea.

Cyclooxygenase-2 (COX-2) – A gene implicated in inflammation and, possibly, tumor formation.

Cyst – Accumulation of fluid or semisolid material within a sack in the body.

Cystitis – An inflammation of the bladder caused by bacteria, chemotherapy or radiation treatments.

Cystoscope – Inspection of the inside of the bladder by means of a telescope.

Cytology – The branch of science that deals with the structure and function of cells. It also refers to tests used to diagnose cancer and other diseases by examination of cells under the microscope.

Cytotoxic – Toxic to cells; cell killing.


Debulking – A procedure that removes a significant part or most of a tumor in cases where it is not possible to remove all of it. This may make subsequent radiotherapy or chemotherapy easier and more effective.

Diagnosis – Identifying a disease by its signs or symptoms, the use of imaging procedures, and/or laboratory findings.

Dosimetrist – a person who plans and calculates the proper radiation doses for cancer treatments.

Drug Resistance – The ability of cancer cells to resist the effects of a specific drug.

Ductal Carcinoma in situ (DCIS) – A form of breast cancer in which cancer cells start in the milk passages (ducts) and have not penetrated the duct walls into the surrounding tissue.

Dysphagia – Difficult or painful swallowing.

Dysplasia – Abnormal changes in cells, which sometimes indicate that cancer may develop.

Dyspnea – Shortness of breath.

Dysuria – Difficult or painful urination.


Edema – The swelling or accumulation of fluid in a body part.

Effusion – A collection of fluid inside a body cavity, such as around the lungs.

Emesis – Vomiting.

Endocrine Therapy – Manipulation of hormones in order to treat a disease or condition.

Endoscope – A hollow tube-like instrument used to look inside a body cavity.

Erythema – Redness of the skin.

Erythrocyte – A red blood cell.

Esophagitis – Soreness and inflammation of the esophagus due to infection, toxicity from radiotherapy, chemotherapy or physical injury.

Estrogen – The female sex hormone produced by the ovaries.

Estrogen Receptor Assay – A laboratory test done on a sample of the cancer to see whether estrogen receptors are present. ER positive cancers are more likely to respond to hormonal therapy.

Estrogen Replacement Therapy – The use of estrogen from sources other than the body.

Excision – Surgical removal of a part of the body.

Extravasation – The leaking of intravenous fluids or drugs into the surrounding tissue.


First-Degree Relative – A parent, sibling, or child.


Gene – Pieces of DNA which contain information for making specific proteins.

Genetic Counseling – The process of counseling people who may have a gene that makes them more likely to develop cancer.

Genetic Testing – Tests performed to see if a person has certain gene changes known to increase cancer risk.

Grading – Classifying cancer cells to provide information about probable growth rate of the tumor and its tendency to spread. Grading plays a role in treatment decisions.

Granulocyte – The most common type of white blood cell. Its function is to kill bacteria.

Gynecologic oncologist – a doctor who specializes in cancers of women’s reproductive organs.


Hematocrit – The percentage of red blood cells in the body. A low hematocrit is a sign of anemia.

Hematologist – A physician who specializes in disease of the blood and bone marrow.

Hematuria – Blood in the urine.

Hemoglobin – A protein in red blood cells that transports oxygen and carbon dioxide and gives blood its red color.

Hemophilia – A bleeding disorder caused by a deficiency in one of the blood clotting factors.

Hemorrhagic Cystitis – A bladder irritation, which may be caused by anticancer drugs.

Hereditary Cancer Syndrome – Conditions associated with cancers that occur in multiple family members because of an inherited, mutated gene.

Herpes Simplex – A common viral infection of the skin or mucous membranes which causes blisters.

Herpes Zoster (Shingles) – A viral infection that settles around the nerves and causes pain and swelling of the skin; the same virus that causes shingles causes smallpox.

High Risk – When the chance of developing cancer is greater than that normally seen in the general population.

Hodgkin’s Disease – An often curable type of cancer that affects the lymphatic system. Named for the doctor who first identified it.

Home health nurse – A nurse who gives medications in the home, teaches patients how to care for themselves, and assesses their condition to see if further medical attention is needed.

Hormone – A chemical substance released into the body by the endocrine glands, such as the thyroid, adrenal or ovaries.

Hospice – A special type of care for people in the final phase of illness, their families and caregivers. The care may take place in the patient’s home or in a homelike facility.


Immune System – The complex system by which the body resists infection by microbes (such as bacteria or viruses) and rejects transplanted tissues or organs.

Immunosuppression – When the body’s immune system is weakened and is less able to fight infection and disease.

Immunotherapy – The artificial stimulation of the body’s immune system to treat and fight disease.

Infiltration – The leaking of fluid or medicine into tissues, which causes swelling.

Inflammation – A condition characterized by redness, heat, pain and/or swelling in tissue.

“Infuse-A-Port” – A quarter size disc inserted below the skin to which a tube is connected and inserted into the bloodstream. Fluids, medicines, and blood products can be administered through the port.

Infusion – Delivering of fluids or medicines into the bloodstream over a period of time.

Intramuscular (IM) – The injection of a drug into a muscle.

Intravenous (IV) – The administration of drugs or fluids directly into the bloodstream.

Invasive Cancer – Cancer that has spread beyond the layer of cells where it started to nearby tissues.


Jaundice – The accumulation of bilirubin in the body resulting in a yellow color to the skin and whites of the eyes.


Lesion – A lump or abscess that may be caused by injury or disease.

Leukemia – Cancer of the blood.

Leukocyte – A type of white blood cell.

Localized – A cancer that is still confined to the site of origin.

Lumpectomy – Removal of a lump and a small amount of surrounding tissue.

Lymphatic System – The tissues and organs (including lymph nodes, spleen, thymus, and bone marrow) that produce and store lymphocytes (cells that fight infection) and the channels that carry the lymph fluid.

Lymphedema – Swelling caused by the obstruction of the lymphatic vessels.

Lymph Nodes – Hundreds of small oval bodies that contain lymph, a clear yellowish fluid resembling blood plasma. Lymph nodes act as our first line of defense against infection and cancers.

Lymphocytes – White blood cells that kill viruses and defend against the invasion of foreign material.

Lymphoma – A cancer of the lymphatic system.


Magnetic Resonance Imaging (MRI) – A procedure using magnetic fields to produce images of the body.

Malignant Tumor – Cancerous; a growth with a tendency to invade and destroy nearby tissue and spread to other parts of the body.

Mammogram – An X-ray of the breast to determine whether abnormal growths are present.

Mastectomy – The surgical removal of all or part of the breast.

Medical Oncologist – A doctor who is specially trained to diagnose and treat cancer with chemotherapy and other drugs.

Medical Physicist – A medical physicist is an individual who is competent to practice, independently, one or more of the sub-fields of medical physics, including therapeutic radiological physics, diagnostic radiological physics, medical health physics, or medical nuclear physics.

Medical technologist – a medical technologist performs a full range of laboratory tests, assisting physicians with the identification of diseases such as cancer.

Melanoma – A cancer of the pigment-forming cells of the skin or the retina in the eye.

Metastasis – The spread of cancer from one part of the body to another by way of the lymphatic system or blood stream.

Monoclonal Antibodies – Laboratory-produced substances that can locate and bind to cancer cells wherever they are in the body.

Morbidity – Death as a result of disease.

Mucous Membrane – The inner lining of the gastrointestinal tract, vagina and nose.

Mucositis – Inflammation of the mucous membranes.

Mutation – Any change in DNA.

Myelogram – An x-ray of the spinal cord after an injection of a dye.

Myeloma – A malignant tumor made up of the bone marrow protein-producing plasma cells.

Myelosuppression – A drop in the blood counts caused by treatment, especially chemotherapy or radiotherapy.


Nadir – The lowest point to which white blood cell or platelet counts fall after chemotherapy.

Needle Biopsy – Removal of a small amount of tissue for diagnosis by placing a needle into a tumor.

Neoplasm – An abnormal growth that may be benign or malignant.

Nephrotoxic – Toxic to the nervous system.

Neutropenic Precautions – Isolation to prevent visitors or hospital staff from carrying an infection into a patient’s room (includes strict hand washing upon entering the patient’s room).

Neutrophils – A type of white blood cell that fights infection.

Nodule – A small lump or tumor that can be benign or malignant.

Non-invasive – A type of growth or procedure which does not invade or destroy nearby tissue.

Nurse Practitioner – A registered nurse with a master’s or doctoral degree who is licensed to diagnose and manage illness and disease, usually working closely with a doctor. In many states, they may prescribe medications.

Nutrition Expert – An individual specially trained in nutrition. This person could be a physician, registered dietitian, nutritionist, or nurse.


Oncogene – A gene that normally directs cell growth, but when altered, can promote cancer.

Oncogenesis – The origin and development of cancer.

Oncologist – A physician who specializes in cancer treatment.

Oncology – The study and treatment of cancer.

Oncology Certified Nurse – A registered nurse with special education and training in cancer care who has attained oncology nursing certification at the basic level.

Oncology Social Worker – A person with a master’s degree in social work who is an expert in coordinating and providing non-medical care to patients.

Ototoxic – Toxic to the ears, generally resulting in ringing in the ears or hearing loss.


Palliative Treatment – Treatment that relieves pain and other symptoms of disease but does not cure the disease.

Pap Smear – Microscopic examination of cells and fluids from the cervix and vagina.

Paracentesis – Removal of fluid from the abdomen by inserting a small needle through the skin.

Partial Response – A decrease in the size of a tumor or in the extent of cancer.

Pathologic Fracture – A break in a bone that has been weakened by cancer or some disease condition.

Pathology – The study of diseases by examination of body fluids and tissue.

Pathologist – A doctor who specializes in the diagnosis and classification of diseases by laboratory tests such as examination of tissue and cells under a microscope. The pathologist determines whether a tumor is benign or cancerous and, if cancerous, the exact cell type and grade.

Pediatric Oncologist – A doctor who specializes in treating cancers of children.

PET (Positron Emission Tomography) Scan – Imagery test that measures metabolic activity.

Petechiae – Tiny areas of bleeding under skin, usually due to a low platelet count.

Phlebitis – A painful swelling of the vein.

Physicist – A specially trained person who ensures the exact amount of radiation is delivered to the treatment site. In consultation with the radiation oncologist, the physicist also determines the treatment schedule that will have the best chance of killing the most cancer cells.

PI 3-kinase – An enzyme that plays a crucial role in cell proliferation and survival.

Placebo – An inactive substance that looks the same as and is administered in the same way as a drug in a clinical trial.

Platelet – A small cell in the blood responsible for clotting.

Polyp – An overgrowth of tissue projecting into a body cavity.

Precancerous – Abnormal changes in a cell that tends to become malignant.

Primary Tumor – The place where the cancer starts to grow.

Primary Site – The place where cancer begins. Primary cancer is usually named after the organ in which it starts. For example, cancer that starts in the breast is always breast cancer even if it spreads (metastasizes) to other organs, such as bones or lungs.

Progesterone – One of the female hormones produced by the ovaries.

Progesterone Receptor Assay – A laboratory test done on a piece of the breast cancer that shows whether the cancer depends on progesterone for growth. Progesterone and estrogen receptor tests provide more complete information to help in deciding the best cancer treatment for the patient.

Prognosis – A statement about the likely outcome of a disease in a specific patient.

Progression – The spreading or growing of disease, with or without treatment.

Progressive Disease – Cancer that is increasing in scope or severity.

Prophylactic – Treatment designed to prevent a disease complication likely to develop but has not yet appeared.

Prophylaxis – Disease prevention measures.

Protein – Basis of body structures such as skin and hair and of substances such as enzymes and antibodies.

Protocol – The treatment plan which includes the drugs, dosages and dates for the cancer treatment.

Psychosocial – The psychological and/or social aspects of health, disease, treatment, and/or rehabilitation.


Radiation Oncologist – A doctor who specializes in using radiation to treat cancer.

Radiation Therapist – A person with special training to operate the equipment that delivers radiation therapy.

Radiation Therapy (RT) – The use of radiation to damage and kill cancer cells.

Radiologist – A physician who specializes in the use of x-rays to treat and diagnose disease.

Recurrence – The reappearance of a disease after previous treatment had caused the disease to disappear.

Red Blood Cells (RBCs) – Cells in the blood that bring oxygen to tissues and take carbon dioxide from tissues.

Regression – The shrinkage of cancer growth.

Rehabilitation – Activities to adjust, heal, and return to a full, productive life after injury or illness.

Relapse – A return of cancer after it has been controlled by treatment.

Remission – Complete or partial disappearance of a disease; the period during which a disease is under control.

Resection – Removal of tissue or organ by surgery.

Resistance – Failure of a tumor to respond to radiotherapy or chemotherapy.

Risk Factor – Anything that increases the chance of developing a disease, including a family history of cancer, use of tobacco products, certain foods or exposure to radiation or cancer causing agents.


Scan – A study using either x-rays or radioactive isotopes to produce images of internal body organs.

Screening – The search for cancer in apparently healthy people who have no cancer symptoms.

Secondary Tumor – A tumor that develops as a result of spreading beyond the original cancer.

Sepsis – Bacterial growth in the blood.

Side Effect – Reaction from drugs or therapies that are not intended or wanted.

Signal Transduction Pathways – Cellular information highways that relay external messages like hormones and growth factors to the inside of cells to trigger physiological responses.

Spiral CT Scan – A detailed picture of areas inside the body created by a computer that scans the body in a spiral path.

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

Staging – An organized process of determining how far a cancer has spread.

Steroids – Drugs used to relieve swelling and inflammation.

Stomatitis – Inflammation or soreness of the mouth.

Surgical Oncologist – A doctor who specializes in using surgery to treat cancer.

Survival Rate – The percentage of people who live a certain period of time. The 5-year survival rate refers to the percent of patients who live at least 5 years after diagnosis, and 5-year rates are used to produce a standard way of discussing prognosis.

Systemic Disease – Disease that involves the whole body rather than just one area.

Systemic Therapy – Treatment that reaches and affects cells throughout the body; for example, chemotherapy.


Thrombophlebitis – Inflammation of veins with blood clots inside the veins.

Toxic Reactions – Serious side effects.

Thrombocyte – Another word for platelet.

Tumor – An abnormal swelling or enlargement of cells or tissues which may be malignant or benign.


Ultrasound – The use of high-frequency sound waves to create an image of the inside of the body.

Unilateral – On one side of the body.

Unproven Therapy – Any therapy that has not been scientifically tested and approved.


Venipuncture – Inserting a needle into a vein in order to obtain a blood sample, start an intravenous infusion or give medication.

Vesicant – A substance that is leaked into the tissues that could cause swelling, tissue damage and destruction.

Virus – A microorganism that can cause an infectious disease; for example, the common cold is a virus.


White Blood Cells (WBCs) – Cells responsible for fighting invading germs, infection and allergy-causing agents.


X-ray – Radiation energy used to diagnose and treat disease.