CA-125 and Ovarian Cancer

Q:  What do you think of the CA-125 blood test to check for ovarian cancer?

A:  CA-125 is a protein produced by a variety of cells in the body. It was found to be high in 80% of women with ovarian cancer. A blood test to measure CA-125 was developed in the early 1980s and it was hoped that the test could be used to detect the presence of ovarian cancer, since there is no way to find it early and most women have no symptoms until the cancer is in advanced stages.

But as it turns out there are also quite a few benign conditions that can raise the levels of CA-125, so it is not a good test for screening. CA-125 test results can be elevated by pregnancy, liver disease, endometriosis, fibroid tumors of the uterus, and diverticulitis, to mention a few of the non-cancerous conditions. It may also be high in patients with cases of cancers of the breast, lung, colon and pancreas.

It is not recommended as a routine test because the chance of having a "false" positive test could lead you on a wild goose chase with a lot of unnecessary worry.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.