Description
Overview: Cancer Antigen 125 (CA-125) is a protein found on the surface of many ovarian cancer cells. While small amounts of CA-125 are normal, high levels can indicate a problem. This test is the gold standard for monitoring ovarian cancer.
Clinical Significance:
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Ovarian Cancer: This is the most common use of the test. Falling levels during chemotherapy indicate the treatment is working, while rising levels may suggest the cancer has returned.
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Other Cancers: Levels can also be elevated in cancers of the endometrium, fallopian tubes, lungs, breast, and gastrointestinal tract.
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Benign Conditions (Important): High CA-125 does not always mean cancer. It can be elevated due to menstruation, pregnancy, endometriosis, pelvic inflammatory disease (PID), or fibroids. This is why it is not used as a general screening test for all women.
When is this test recommended?
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To check if ovarian cancer treatment (surgery/chemotherapy) is effective.
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To monitor for cancer recurrence after treatment is finished.
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To evaluate a woman with a pelvic mass (lump) to help determine if it is likely benign or malignant.
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To screen high-risk women (those with a strong family history or BRCA mutations), often in combination with a transvaginal ultrasound.
Sample Requirements:
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Specimen: Serum.
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Container: Gold Top (SST) or Red Top Tube.
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Preparation: No fasting is typically required. Avoid testing during menstruation if possible, as levels can be naturally higher.
