The CA-125 blood test is the leading test used in the diagnosis and management of ovarian cancer. CA-125 is a protein that is present on the surface of ovarian cancer cells. Created in the fallopian tubes and abdominal cavity lining, cancer antigen 125 is found in higher concentration in tumor cells than in normal cells.

CA-125 is used as a tumor marker and can identify the existence of ovarian and other forms of cancer. The cancerous cells release the protein into the blood stream. The cancer antigen 125 test determines the amount of the protein in the blood stream. Physicians use the blood test to do the following:

• See if the cancer treatments are effectively treating the cancer
• Conclude if the cancer has returned
• Determine the origin of the cancer

In 80% of the women with ovarian cancer, CA-125 protein levels are elevated. While the elevated levels of protein are a sign of ovarian cancer, there can be other potential causes. Menstruation, pregnancy, pelvic inflammatory disease and ovarian cysts can also increase the levels of protein. The Health Testing Centers offers this as well as other cancer antigen blood tests.