Cancer antigen 15-3 (CA 15-3)
The cancer antigen 15-3 (CA 15-3) biomarker test is used to monitor breast cancer and its response to treatment. The CA 15-3 antigen is a protein released into the bloodstream by breast cancer, various other cancers, and even some benign (noncancerous) conditions.
CA 15-3 is one of several substances classified as tumor markers, which may increase as a malignancy progresses and decrease as a tumor gets smaller as it responds to cancer therapy.
This test is used to monitor response to breast cancer treatment and disease recurrence.
