Skip to main content

Understanding CA 125 Levels


Women who are suspected of having ovarian cancer and women who have been diagnosed with ovarian cancer often receive a blood test to measure their CA 125 level. This association between ovarian cancer and CA125 often leads to confusion and misunderstanding about what this test means for diagnosis of ovarian cancer and/or its impact on the clinical management of ovarian cancer.

This booklet will take you through the basics of what you need to know about CA 125 — what it is, what it’s measuring and what the values mean. And hopefully, this information will help you better understand how this test is used and interpreted in your treatment and follow-up.

The information in this booklet was originally provided to over 300 women who participated in a free telephone workshop organized by the Foundation for Women’s Cancer, formerly the Gynecologic Cancer Foundation. Dr. Thomas J. Herzog, Director, Division of Gynecologic Oncology, Columbia University, and Dr. Robert L. Coleman, Professor & Ann Rife Cox Chair for Gynecology, Division of Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, conducted the workshop.

Please click here to view the entire publication.