Can ovarian cancer be detected through a blood test?

To help diagnose ovarian cancer, a healthcare professional may order blood tests to check for blood counts (red blood cells, white blood cells and platelets), to measure kidney and liver function and to assess overall health status.

In addition, the healthcare professional may order a blood test that checks for CA-125, a protein found in the blood of many women with ovarian cancer. However, other conditions, including normal ovulation, endometriosis and pelvic inflammatory disease can also raise CA-125 levels. And some women with ovarian cancer may still have normal levels of CA-125.

Because of these problems, the CA-125 blood test is not recommended for women at average risk of ovarian cancer, but it may be used for women at high risk or for those with symptoms suggesting ovarian cancer. If the CA-125 is elevated, consultation with a gynecologic oncologist is recommended.
David A. Fishman, MD
Gynecologic Oncology
The ability to detect human malignancy by a simple blood test has long been an objective in medical screening. A suitable test or examination to screen for a disease should have both high sensitivity (the probability of the test being positive in individuals with disease) and high specificity (the probability of the test being negative in those without the disease). Developing a highly specific screening test is a major concern for ovarian cancer because the majority of women who test positive on screening will require surgery to confirm the diagnosis. A screening test with low specificity requires a large number of operations to detect one case of ovarian cancer, which is not acceptable to
patients or their doctors. For example, in postmenopausal women, even a screening test with 98% specificity would result in operations on 50 women who do not have cancer for every one case of ovarian cancer found during surgery.

Because the incidence of ovarian cancer in the general population is low, approximately 1.8%, the specificity of the CA-125 blood test (a test currently used for ovarian cancer) is unacceptably low for screening for ovarian cancer in the general population.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.