Synonyms:  CA 15-3

Why It Is Done

When you have been or are being treated for invasive breast cancer.
CA 15-3 sometimes also is used to give a doctor additional information about where the cancer may have spread (such as into the bones or the liver) and a general sense of how much cancer may be present.

Test Overview

Cancer antigen 15-3 (CA 15-3) is a normal product of breast cells; it is produced by a gene that is often over-expressed (i.e., the body makes too many copies) in cancerous breast tumors, leading to an increased production of CA 15-3 and the related Cancer antigen 27.29.
CA 15-3 also may be elevated in healthy people and in individuals with other cancers, conditions, or diseases, such as colorectal cancer, lung cancer, cirrhosis, hepatitis, and benign breast disease.
CA 15-3 is not sensitive or specific enough to be considered useful as a tool for cancer screening. Its main use is as a tumor marker to monitor a patient’s response to breast cancer treatment and to watch for breast cancer recurrence

How To Prepare

No special preparation is required before having this test