CA15.3

The CA15.3 test measures the glycoprotein marker Cancer Antigen 15.3 in the blood. It is primarily used as a tumor marker for breast cancer. It is an important tool to monitor patients of breast cancer, to know treatment effectiveness in patients undergoing cancer treatment, and to monitor the relapse or metastasis status (spread to other parts of the body). 

CA15.3 is a glycoprotein marker that is raised in breast cancer and a few cases of carcinomas of the ovary, colon, pancreas, lung, and non-malignant conditions such as cirrhosis, hepatitis, benign breast disease, endometriosis, pelvic inflammatory disease, and liver disease. It can also be increased during pregnancy. It is noteworthy that CA15.3 does not cause cancer; rather, it is released by tumor cells, making it useful as a marker to trace the course of cancer. Breast cancer is one of the most common cancers worldwide. Although it can occur in both men and women, breast cancer is most prevalent in women. Usually, it involves rapid changes in the breast shape, color, etc. The breast cells grow at an abnormal rate in an individual affected by the disease. Early detection and monitoring are crucial for improving outcomes and survival rates.

The CA15.3 test is typically recommended for individuals who have been diagnosed with breast cancer, particularly those with advanced stages of the disease. This test is advised only to monitor cancer progression or response to treatment and not as a screening test because, at the initial stage of cancer, the CA15.3 level does not rise significantly. Their levels are highest when breast cancer has spread to other parts of the body. An increase in values in patients treated for breast cancer may indicate recurrent disease and require additional tests or procedures for work-up. Patients are advised to do follow-up testing preferably through the same laboratory as different assays can give different result values.

The CA15.3 is valuable in assessing how well an individual is responding to treatment. Further, this tumor marker test helps healthcare advisors determine whether a cancer is stable, growing, shrinking, or has relapsed.

Usually, no special preparation is needed before undergoing the CA15.3 test. However, it is important to provide a brief clinical history/ doctor's prescription at the time of sample collection. Additionally, tell your doctor about any medications and supplements you are taking as certain medications can affect your test results 

Reference ranges are approximate and may vary based on factors such as age, gender, medical history, etc. Moreover, patients with confirmed breast cancer may show normal CA 15.3 levels before treatment initiation. Hence the CA15.3 test, regardless of CA 15.3 levels, should not be interpreted as absolute evidence for the presence or absence of malignant (that which can spread to other parts) cancer.

Abnormal test results require an expert interpretation; therefore, never try to self-medicate at home based solely on these results, and always consult a doctor for a proper understanding of the test results.