CA125 (Cancer Antigen 125)
Understanding CA125 (Cancer Antigen 125)
What is CA125 (Cancer Antigen 125)?
A CA125 (Cancer Antigen 125) test measures the amount of protein CA125 (Cancer Antigen 125) in blood. It is a tumor marker used to monitor certain cancers (particularly ovarian cancer) during and after therapy. In some high-risk individuals, the test may be used to look for early signs of an ovarian tumor. Serial measurements help to detect cancer recurrence and predict response to therapy. This test is not considered useful for cancer detection screening in the normal population.
CA125 is a protein found on the surface of ovaries, fallopian tubes, and body linings. High levels of CA125 in the blood might indicate ovarian cancer or other cancers like cervical, liver, pancreatic, lung, colon, stomach, biliary tract, uterine, fallopian tube, breast, and endometrial cancers. However, raised CA125 levels can also be caused by non-cancerous conditions such as menstruation, endometriosis, ovarian cysts, and pregnancy.
Your doctor may recommend this test if you experience symptoms suggestive of ovarian cancer, such as persistent abdominal or pelvic pain, bloating, difficulty eating, or urinary symptoms. It's also used to check for cancer recurrence or how well treatment is working in people with a history of ovarian cancer. Additionally, your doctor may recommend a CA125 (Cancer Antigen 125) test if you have risk factors such as increasing age, being overweight, having family members with cancer, or if you've never been pregnant.
Fasting is not needed to get a CA125 (Cancer Antigen 125) test done. However, talk to your doctor if you are taking any prescription medications or over-the-counter medications, as some of them may interfere with your test results. It is advisable not to get your test during menstruation or pregnancy as CA125 levels may show variations.
Test results may differ based on how the test is done. Values obtained with different methods cannot be used interchangeably for monitoring purposes. This test alone doesn't confirm or rule out cancer definitively because it can sometimes give wrong results, showing cancer when it's not there (false positives) or missing cancer when it is (false negatives). Therefore, talk to your doctor about your specific test results. Narrate your complete medical history to help them correlate your clinical and laboratory findings and formulate your treatment plan.
What is CA125 (Cancer Antigen 125) used for?
A CA125 (Cancer Antigen 125) test is done:
- To detect ovarian cancer in high risk women.
- To monitor the effectiveness of ovarian cancer treatment.
- To detect recurrence of cancer.
- To help differentiate between benign and malignant pelvic masses.
What does CA125 (Cancer Antigen 125) measure?
CA125 is a protein found in most ovarian cancer cells and some normal tissues. A CA125 (Cancer Antigen 125) test is commonly advised to detect ovarian cancer by measuring the amount of CA125 protein in the blood. A deranged level of CA125 antigen may indicate the presence of certain cancers, primarily ovarian cancer or other non-cancerous conditions, including endometriosis, pelvic inflammatory disease, ovarian cysts, etc.
Interpreting CA125 (Cancer Antigen 125) results
Interpretations
High levels may be seen in:
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Ovarian cancers
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Pregnancy
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Menstruation
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Ovarian cysts
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Inflammatory diseases of the Pelvis
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Cirrhosis
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Hepatitis
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Endometriosis
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Other tumors, such as lung, colorectal, breast, or gastrointestinal tumors