CA-125 is a protein released by cancer cells that is also made by inflamed normal cells that line body parts. This substance is shed into bodily fluids and finds its way into the bloodstream. A CA- 125 assessment is performed on a blood sample. The assay measures the concentration of CA-125 in the liquid portion of the blood (serum).

CA-125 testing is best used for monitoring changes that might happen in your cancer growth over time.

Please note:About 20% of women who have ovarian cancer never have elevated CA-125 levels. Also, some women have naturally elevated levels of CA-125, so an elevation of this protein does not necessarily mean that cancer is present. That is why it is critical to use CA-125 as part of a diagnostic and monitoring regimen. It is not suitable to use the test as a screening test for the general public.