Quick Facts
- Sample: Blood
- Fasting: No fasting required. Stop biotin 72 hours before collection. For CA-125, test at least 3 weeks after chemotherapy and 2 months after abdominal surgery. Avoid testing during menstruation; ideally wait 1 week after your period ends.
- Turnaround: 1-2 business days. May take longer due to weather, holidays, or lab delays.
What This Test Measures
This test measures Cancer Antigen (CA) 125, a glycoprotein antigen, in a blood sample. CA-125 is directly measured from serum and is not reported as a ratio or calculated value.
CA-125 testing is used to monitor ovarian cancer during and after treatment. Providers may check a baseline CA-125 level before treatment, then compare later results to that baseline. A decline in CA-125 during and after treatment usually points to successful treatment, while an increase after treatment may indicate the disease has returned. In some cases, this test can also help check for early signs of ovarian cancer in women at high risk for the disease. CA-125 is not accurate enough to detect ovarian cancer in all women, because many other conditions can also raise CA-125 levels. This test is available for men and women, though it is most often ordered for women in connection with ovarian cancer. Elevated CA125 levels in men may occur due to non-cancerous conditions such as liver disease, heart failure, or inflammation of the abdominal lining, as well as certain cancers
Benefits
- Measures CA-125 protein levels directly from a blood sample
- Helps monitor how well ovarian cancer treatment is working
- Tracks CA-125 changes that may signal disease recurrence
- May help evaluate early signs of ovarian cancer in high-risk women
- Available for both men and women
- Simple blood draw with no fasting required
Who Is This Test For?
- Women being monitored during ovarian cancer treatment
- Women being monitored for ovarian cancer recurrence after treatment
- Women at high risk for ovarian cancer, in some cases
- Anyone whose healthcare provider recommends CA-125 testing
- Men or women ordered for CA-125-related evaluation by a provider
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test measures Cancer Antigen (CA) 125, a protein, in your blood. It is used to help monitor ovarian cancer during and after treatment, including tracking whether CA-125 levels decline (which usually points to successful treatment) or rise after treatment (which may suggest recurrence). In some cases, it can also help evaluate early signs of ovarian cancer in women at high risk. This test alone is not sufficiently accurate to detect ovarian cancer in all women, since other conditions can also raise CA-125 levels.
2. Who is this test for, and when should it be ordered?
This test may be ordered for women currently undergoing ovarian cancer treatment who need monitoring, women being followed after treatment for possible recurrence, and women at high risk for ovarian cancer in certain situations. A healthcare provider may first establish a baseline CA-125 level before treatment, then order follow-up testing during and after treatment to track changes against that baseline. The test is also available to men and women whose healthcare provider recommends CA-125 testing as part of their care. It does not replace a full clinical evaluation.
3. How does this test differ from other cancer-related tests?
This test focuses on a single biomarker, CA-125, measured directly from a blood sample rather than reported as a ratio or calculated value. Because CA-125 can also be affected by conditions unrelated to ovarian cancer, its supported role is narrower than a general cancer screen: it is intended for monitoring ovarian cancer during and after treatment and, in some cases, evaluating early signs in high-risk women, rather than serving as a standalone diagnostic test.
4. Do I need to fast before this test?
No fasting is required for this test. Stop biotin at least 72 hours before collection. If you are being tested in connection with ovarian cancer treatment, collect the sample at least 3 weeks after primary chemotherapy and at least 2 months after abdominal surgery. Where possible, avoid testing during menstruation, since CA-125 levels can be significantly elevated during menses and may be misinterpreted; schedule testing at least one week after your menstrual period ends for the most accurate results.
5. How quickly will I get results?
Results are typically available in 1-2 days. Turnaround may take longer based on weather, holidays, or lab delays.
6. How do I interpret the results?
Interpreting CA-125 results depends on the exact result, your medical history, your clinical context, and other relevant findings. An elevated CA-125 result does not automatically mean cancer is present, since conditions such as pregnancy, pelvic inflammatory disease, normal menstruation, endometriosis, endometrial and fallopian tube cancers, noncancerous uterine growths like fibroids, and pancreatic cancer can also raise CA-125. A normal result does not automatically rule out cancer. When CA-125 is used for treatment monitoring, a decline usually points to successful treatment, and an increase after treatment may suggest recurrence, though these trends do not guarantee a specific clinical conclusion on their own. Results are best reviewed alongside other laboratory findings, imaging, or clinical evaluation as appropriate.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
7. What should I do if my results are abnormal?
Review an abnormal result with a qualified healthcare provider, who can determine whether additional evaluation is appropriate based on your full clinical picture. Do not start, stop, or change any medication or treatment based on this result alone.
8. How often should I get tested?
Testing frequency depends on your individual situation and should be determined by your healthcare provider. For ovarian cancer monitoring, a provider may check a baseline level before treatment and follow up with additional testing during and after treatment as directed. Follow your healthcare provider's guidance for how often to repeat this test.
Pre-test preparation
No fasting is required. Stop biotin at least 72 hours before collection. For the CA-125 test, collect at least 3 weeks after primary chemotherapy and 2 months after abdominal surgery. Avoid testing during menstruation when possible, as CA-125 levels can be significantly elevated during menses, potentially leading to misinterpretation. Schedule testing at least one week after the completion of the menstrual period for the most accurate results.
