- Tumor marker is a substance present in or produced by a tumor or by the host, that can be used for differentiating neoplastic from normal tissue based on measurements in body fluids, secretions, cells, and/or tissues. Markers are used in diagnosis, staging and prognosis of cancer, provide an estimation of tumor burden, and serve for monitoring effects of therapy, detecting recurrence, localization of tumors, and screening in general populations. Tumor markers have been categorized as follows: enzymes, isoenzymes, hormones, oncofetal antigens, carbohydrate epitopes, oncogene products, and genetic changes. There is no identified tumor marker that fits the ideal specificity profile.
Definition from: NCI Thesaurus via Unified Medical Language System at the National Library of Medicine
- A substance sometimes found in the blood, other body fluids, or tissues. A high level of tumor marker may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (prostate cancer). Also called biomarker.
National Cancer Institute
Related discussion in the Handbook
See also Understanding Medical Terminology.