Cancer Terms & Definitions

Cancer has a whole language of its own. Review this list of terms before your next appointment. And if you don’t understand something someone has said, be sure to ask them to slow down and explain it in other words.

Basic Cancer Vocabulary

Acute: Describes symptoms that are severe, but only last a short time.

Benign: Describes a tumor that is not cancerous and doesn’t usually spread to other parts of the body.

Biopsy: Procedure to remove a tissue sample for examination under a microscope. Used to diagnose cancer.

Cancer: Diseases with unusual cell growth that can move into nearby tissues.

Chemotherapy: Treatment for cancer that uses drugs to kill cancer cells.

Chronic: Describes a disease or condition that lasts for a long time and often develops slowly.

Imaging test: A procedure that uses x-ray, PET/CT, MRI, etc, to creates pictures of the inside of the body. The images are used to diagnose, plan treatment, evaluate the effectiveness of treatment or observe a disease.

Invasive cancer: When cancer spreads outside the part of the body where it first began growing.

Laboratory test: A procedure that examines a sample of blood, urine, etc., to diagnose, plan treatment, evaluate the effectiveness of treatment or observe a disease.

Localized cancer: Cancer that has not spread.

Lymphatic system: A network in the body of small tubes and organs that carry fluid around the body. Cancer can spread through the lymphatic system.

Metastasis: When cancer spreads to another part of the body.

Oncologist: A doctor who cares for people diagnosed with cancer.

Oncology: The study of cancer.

Pathologist: A doctor who specializes in interpreting laboratory tests to diagnose disease.

Precancerous: Describes cells that could become cancerous.

Predisposition: When someone’s genetics make them more likely to develop a disease under certain conditions.

Prognosis: A prediction about how a disease will play out and a person’s chances of recovery.

Radiation therapy: A medical treatment using beams of high-energy or radioactivity to damage cancer cells.

Staging: A way to describe the spread and impact of cancer in the body.

Tumor: A lump in the body that is formed when normal cells mutate and grow rapidly. Not all tumors are cancerous.

Other Resources for Cancer Terminology

Basic cancer terms from

Dictionary of cancer terms from the National Cancer Institute

Definitions and pronunciation guide from the American Cancer Society

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