What is Cancer Antigen 125?

A CA 125 test measures the amount of the protein CA 125 (cancer antigen 125) in your blood. A CA 125 test may be used to monitor certain cancers during and after treatment. In some cases, a CA 125 test may be used to look for early signs of ovarian cancer in people with a very high risk of the disease.

What the Cancer Antigen 125 test used for?

A CA-125 blood test may be used to:

• Monitor treatment for ovarian cancer. If CA-125 levels go down, it usually means the treatment is working.
• Check to see if cancer has come back after successful treatment.
• Screen women who are at high risk for ovarian cancer.

How is the procedure performed?

CA 125 is usually measured from a venous blood sample. It can also be measured in fluid from the chest or abdominal cavity. A blood sample drawn from a vein in your arm. You may want to wear a shirt with sleeves that can easily be rolled up to make it easier to collect the blood sample. This usually takes less than five minutes.

What will be the results interprets?

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results. In most laboratories, the normal value is 0 to 35 units/ml.

If you are being treated for ovarian cancer, you may be tested several times throughout your treatment. If testing shows your CA-125 levels have gone down, it usually means the cancer is responding to treatment. If your levels go up or stay the same, it may mean the cancer is not responding to treatment. If you are not being treated for ovarian cancer and your results show high CA-125 levels, it can be a sign of cancer. But it may also be a sign of a noncancerous condition, such as:

• Endometriosis, a condition in which tissue that normally grows inside the uterus also grows outside the uterus. It can be very painful. It may also make it harder to get pregnant.
• Pelvic inflammatory disease (PID), an infection of a woman's reproductive organs. It's usually caused by a sexually transmitted disease, such as gonorrhea or chlamydia.
• Uterine fibroids, noncancerous growths in the uterus
• Liver disease
• Pregnancy
• Menstruation, at certain times during your cycle