CA 125 Tumor Marker: What Does the Result Mean?

CA 125 Tumor Marker Test is a tool to monitor treatment for ovarian cancer and detect recurrence. It is sometimes used to help detect early ovarian cancer in high-risk cases, or evaluate a lump located in the pelvic area (pelvic mass).

Normal Results:

0 to 35 U/mL.

What Does the Result Mean?

  • A decreased CA-125 level indicates that the cancer is responding to treatment.
  • A similar or increased CA-125 level indicates that the cancer may not be responding to therapy.
  • A high CA-125 level after treatment is complete may indicate that the cancer has come back.
  • A baseline CA-125 level that is normal, is not useful, when the person is a woman who has been diagnosed with ovarian cancer. Follow-up exams are needed.
  • A significantly elevated CA-125 level indicates that there may be ovarian cancer, when the person is a woman with a pelvic mass or a high risk of developing ovarian cancer.


Keywords: CA 125 Tumor Marker, CA-125, Cancer Antigen 125

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