Should I ask my doctor for a CA 125 blood test to screen for ovarian cancer?
Answers from Shannon K. Laughlin-Tommaso, M.D.
The cancer antigen 125 (CA 125) blood test isn't recommended for women with an average risk of ovarian cancer.
While women with ovarian cancer often have an elevated level of CA 125, an elevated CA 125 level doesn't always mean you have ovarian cancer. Some women with ovarian cancer never have an elevated CA 125 level.
Many other conditions also can cause an elevated CA 125 level, including:
- Liver cirrhosis
- Normal menstruation
- Pelvic inflammatory disease
- Uterine fibroids
For these reasons, doctors don't recommend CA 125 testing in women with an average risk of ovarian cancer.
Women with a high risk of ovarian cancer, such as those with mutations in the BRCA1 and BRCA2 genes, which increase the risk of breast and ovarian cancers, may consider periodic CA 125 testing. But even in these high-risk situations, there's some disagreement about the usefulness of the CA 125 test.
A study of 78,216 women ages 55 to 74 randomly selected to receive either an annual CA 125 test and pelvic ultrasound screening or the usual medical care showed that CA 125 testing and ultrasound screening did not reduce ovarian cancer deaths. The study also found that false-positive tests led to additional testing and procedures that sometimes resulted in serious complications.
If you're concerned about your risk of ovarian cancer, ask your doctor about your screening options and ways to reduce your risk.
Shannon K. Laughlin-Tommaso, M.D.
Aug. 19, 2017
- AskMayoExpert. Ovarian cancer screening. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
- Screening for ovarian cancer. Rockville, Md.: U.S. Preventive Services Task Force. https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/ovarian-cancer-screening. Accessed July 18, 2017.
- Buys SS, et al. Effect of screening on ovarian cancer mortality: The prostate, lung, colorectal and ovarian (PLCO) cancer screening randomized controlled trial. JAMA. 2011;305:2295.
- Smith RA, et al. Cancer screening in the United States, 2016: A review of current American Cancer Society guidelines and current issues in cancer screening. CA: A Cancer Journal for Clinicians. 2016;66:95.
- Carlson KJ. Screening for ovarian cancer. https://www.uptodate.com/contents/search. Accessed July 18, 2017.