About CA125
The CA125™ Test is a blood test that measures the level of a protein often found in women diagnosed with ovarian cancer. Physicians use the results of the CA125 test to monitor a patient’s response to treatment and for recurrence of disease. Clinical practice guidelines recommend patients be monitored following initial treatment every 2 to 4 months for 2 years, every 6 months for 3 years, and then annually with CA125 (if it was elevated) and a physical examination.14
Not all women diagnosed with ovarian cancer will have elevated CA125; in addition, some women who have elevated CA125 will not have cancer. There are a number of reasons that this occurs. First, there are other conditions that can cause an elevation in the CA125 value. Some of these conditions include menstruation, endometriosis, pregnancy, pelvic inflammatory disease, and benign ovarian cysts. Second, not all cancerous tumors cause an elevation of CA125 in the blood.
There are different formulations of the CA125 test available in laboratories today. These differences can create variations in the results reported by the laboratory. To ensure that patients have consistent and valid test results, they are encouraged to use the same laboratory for each test.
