Tumor Marker
Also known as: tumour marker, biomarker
A substance, usually measured in blood, that can indicate the presence or activity of a cancer.
Definition
Tumor markers are substances — usually proteins — that are produced by cancer cells or by the body in response to a cancer. They can be measured in blood, urine or tissue and are used (selectively) to help diagnose certain cancers, monitor response to treatment, or detect recurrence during follow-up.
Common examples include CA 15-3 in breast cancer, CA 125 in ovarian cancer, CEA in colorectal cancer, AFP in liver and germ cell tumours, PSA in prostate cancer, and beta-HCG in germ cell tumours. Markers are interpreted as part of the full clinical picture — they are rarely diagnostic on their own, because levels can also rise in non-cancer conditions.
See also
- Recurrence — The return of cancer after a period of being undetectable.
- Staging — The process of finding out how large a cancer is and whether it has spread.
- Prognosis — A doctor's best estimate of how a cancer is likely to behave and respond to treatment.
- Genetic Testing — Tests that examine genes to find inherited risk or to guide cancer treatment.
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Medically reviewed by
Dr. Rehan Abdullah
Dr. Rehan Abdullah is a dual-trained clinical and radiation oncologist with over a decade of experience treating both solid tumours and hematologic malignancies. He serves as Consultant Oncologist at INMOL Hospital and sees patients at Farooq Hospital and Healthnox Medical Center, Lahore. Read full profile →
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