Cancer Antigen 125 (CA-125)

CA-125 (Cancer Antigen) Test, Carbohydrate Antigen (CA-125) Test

Test Overview

A cancer antigen 125 (CA-125) is a protein found on the surface of many ovarian cancer cells. It also can be found in other cancers and in small amounts in normal tissue. A CA-125 test measures the amount of this protein in the blood.

CA-125 is used as a tumor marker—which means the test can help show if some types of cancer are present. Most often, the CA-125 test is used to check how well treatment for ovarian cancer is working or to see if ovarian cancer has returned.

	Go to top of page	Go to next section
Author:	Maria G. Essig, MS, ELS	Last Updated: July 2, 2007
Medical Review:	Adam Husney, MD - Family Medicine Douglas A. Stewart, MD - Medical Oncology
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.