A CA 125 test may be recommended by a doctor for a variety of reasons, including:
- To keep track of cancer treatment: If one has ovarian, endometrial, peritoneal, or fallopian tube cancer, doctors may advise to get a CA 125 test done on a regular basis to evaluate progress and response to treatment.
However, such surveillance has not been proved to improve the fate of ovarian cancer patients and may result in additional and unneeded rounds of chemotherapy or other treatments.
- If one is at high risk for ovarian cancer: If one has a significant family history of ovarian cancer or the BRCA1 or BRCA2 gene mutation, doctors may advise a CA 125 test as a method of screening for ovarian cancer.
For patients at very high risk, some clinicians may prescribe CA 125 testing in conjunction with transvaginal ultrasound every six months.
Some patients with ovarian cancer, however, may not have an elevated CA 125 level. Furthermore, there is no evidence that CA 125 screening reduces the risk of dying from ovarian cancer. An increased CA 125 level may encourage the doctor to subject the patient to needless and even hazardous tests.
To screen for a recurrence of cancer: Rising CA 125 levels may suggest that ovarian cancer has returned following the treatment. Regular CA 125 monitoring has not been proved to enhance outcomes in ovarian cancer patients but they may help in monitoring the prognosis.