CA 125; Cancer Antigen 125

The CA 125 (Cancer Antigen 125) test is a blood test that measures the level of CA 125, a protein commonly used as a tumor marker. Elevated CA 125 levels are most frequently associated with ovarian cancer, although increased levels may also occur in several non-cancerous conditions. This test is primarily used to monitor treatment response, detect recurrence of ovarian cancer, and assist in the evaluation of patients with symptoms suggestive of ovarian disease.

The CA 125 test is commonly recommended for individuals with symptoms such as abdominal bloating, pelvic pain, abdominal swelling, unexplained weight loss, or persistent changes in urinary or bowel habits, particularly when ovarian cancer is suspected. It is also widely used during and after cancer treatment to monitor disease progression and evaluate the effectiveness of therapy. However, elevated CA 125 levels may also occur in menstruation, pregnancy, endometriosis, pelvic inflammatory disease (PID), liver disease, and other benign conditions. Therefore, the CA 125 test is not a standalone diagnostic test and should always be interpreted together with clinical findings, imaging studies (such as ultrasound or CT scan), and other laboratory investigations. This comprehensive approach helps healthcare providers make accurate diagnostic and treatment decisions.