Cancer Antigen 125 (CA-125)
Why It Is Done
The test for cancer antigen 125 (CA-125) is used to:
- Check to see if treatment for cancer is working. If the level of CA-125 is going down, it usually means that the treatment is working.
- Check to see if ovarian cancer has returned.
- Check to see if the ovary is the main site of cancer in a woman. If a doctor has found a cancer that has spread to another part of the body (metastatic cancer), he or she may do a CA-125 test to find out where the cancer started. High levels of CA-125 are a strong sign that the cancer started in the ovary. But other types of cancer can increase CA-125 levels too.
The CA-125 test is not recommended as a screening test for ovarian cancer at this time because it often has Reference false-positive results Opens New Window. But the CA-125 test and an Reference ultrasound Opens New Window scan may be used to test women who have a high chance of developing ovarian cancer. Women have a high risk of getting ovarian cancer if they have a family history of ovarian cancer or certain changes (mutations) in their Reference DNA Opens New Window (BRCA1 or BRCA2).
|By:||Reference Healthwise Staff||Last Revised: Reference May 6, 2011|
|Medical Review:||Reference Anne C. Poinier, MD - Internal Medicine
Reference Thomas M. Bailey, MD - Family Medicine