Tumor markers, such as cancer antigen (CA) 125, are substances that can often be detected in higher-than-normal amounts in the blood, urine or body tissues of some people with certain types of cancer. Currently, the main use of tumor markers is to assess how the cancer is responding to treatment.
CA 125 isn't specific to just one type of cancer. But women with ovarian cancer often have elevated CA 125 levels.
Not all women with elevated CA 125 levels have ovarian or other cancer. Many other conditions can cause elevated CA 125 levels, including:
- Endometriosis
- Pancreatitis
- Pregnancy
- Normal menstruation
- Pelvic inflammatory disease
Also, some women with ovarian cancer never have an elevated CA 125 level. Because of these limitations, this test isn't useful as a routine screening for ovarian cancer.
CA 125 is primarily used during and after treatment of ovarian cancer. In women receiving chemotherapy for ovarian cancer, a decreasing CA 125 level often indicates that the cancer is responding to treatment. A rising level may indicate a return or continued growth of the cancer.
If you have an elevated CA 125 level but haven't been diagnosed with cancer, your doctor may recommend further testing to look for the cause. Research continues on the use of many tumor markers in detection, diagnosis and treatment of cancer.
