CA 15-3 Blood Test

About the test

CA 15-3 is a biomarker that is associated with some breast cancers. It is not used as a screening tool for breast cancer as it is frequently negative in early breast cancer. It is usually used to monitor the response to treatment for patients with metastatic breast cancer and is usually performed at the request of an oncologist. If you have found a breast lump or have noticed changes to the skin of your breast or changes to your nipple, you should see a doctor.

This test measures the levels of CA 15-3 in your blood and serves as a valuable marker for monitoring disease progression and treatment response in individuals already diagnosed with breast cancer. This is not a cancer screening biomarker.

CA 15-3 levels are particularly useful in tracking the course of breast cancer and monitoring treatment effectiveness. Serial measurements of CA 15-3 levels over time can help healthcare professionals assess the response to therapy and evaluate the progression of metastatic breast cancer. A decline in CA 15-3 levels may indicate a positive response to treatment, while an increase in levels may suggest disease progression or recurrence.

1 Biomarker