CA 15.3 is a tumor marker primarily associated with breast cancer, and the CA-15.3 Serum Test is utilized to monitor therapy effectiveness and detect potential disease recurrence, particularly in cases of metastatic breast cancer. This blood test measures the concentration of CA-15.3 antigen in the serum, providing valuable information about the progression and response to treatment for breast cancer patients.

Who Needs to Undergo a CA 15.3 Blood Test?

Your doctor may prescribe CA 125 test if –

1. You’ve been diagnosed with breast cancer (to see how well treatment is working).
2. You’ve previously been treated for breast cancer (to see whether the cancer has returned or spread).

Preparing For CA 15.3 Blood Test

Although there are no special requirements for the CA 15.3 blood test preparation, keep the following things in mind:

• Inform your doctor about any medications you are consuming.
• Intimate your doctor regarding any allergies you may have.
• If there has been an incident of an animal bite, inform your doctor about it. Antibodies would be present in your body because of the incident that may interfere with the test results.

What do the results mean?

Patients with metastatic breast cancer may have multiple CA 15.3 tumor marker tests during the course of treatment. This is because antigen levels change in response to disease progression or regression. Increasing CA 15.3 levels may suggest the cancer has grown or recurred, while decreasing levels may indicate the cancer is getting smaller.