• No fasting is required for this test. You may eat and drink normally unless advised otherwise.
• Inform the laboratory team about any ongoing cancer treatment, medications, or recent medical procedures.
• Share your medical history, including previous cancer diagnosis or treatment details, with your doctor.
• Avoid strenuous activity immediately before sample collection.
• Carry your doctor’s prescription and valid ID proof at the time of testing.
• For follow-up tests, try to use the same laboratory for consistent comparison of results.

The CA 15-3 test measures the level of a specific protein that may be released into the bloodstream by certain cancer cells, particularly breast cancer cells. Elevated levels of CA 15-3 are most commonly associated with advanced or metastatic breast cancer, although mild elevations may also be seen in non-cancerous conditions.

Doctors commonly recommend the CA 15-3 test to:

• Monitor response to breast cancer treatment
• Detect recurrence of breast cancer
• Assess disease progression in advanced cases
• Support diagnosis in conjunction with other clinical findings
• Evaluate treatment effectiveness over time

The test involves collecting a small blood sample from a vein in the arm. The procedure is quick, safe, and minimally uncomfortable. Results are interpreted over time rather than as a single value, as trends in CA 15-3 levels are more meaningful than individual readings.

It is important to note that elevated CA 15-3 levels do not always indicate cancer. Certain benign conditions, such as liver disease or other non-cancerous disorders, may also cause increased levels. Therefore, results are always interpreted alongside imaging studies, clinical evaluation, and other diagnostic tests.