Serum CA-125 in women with endometriosis and chronic pelvic pain

Since serum CA-125 concentrations are increased in women with endometriosis, the authors evaluated CA-125 levels to determine whether this serum test would be useful in differentiating between pelvic pain due to endometriosis and other causes. During a 30-month period, 163 women who had had pelvic pain for at least 3 months had a CA-125 level obtained prior to surgery. Serum CA-125 was measured by an immunoradiometric assay. Of the 82 women with endometriosis, 66 (80%) had CA-125 concentrations greater than or equal to 16 U/ml (95% upper limit). The frequencies of elevated levels in minimal, mild, moderate, and severe endometriosis were 52, 86, 100, and 100%, respectively. Of the 81 women without endometriosis, 5 (6%) had elevated concentrations. With the use of serum CA-125 determinations for the detection of endometriosis, the sensitivity was 80%, the specificity was 94%, and the accuracy was 93% when the prevalence of endometriosis was 50%. The authors conclude that determination of CA-125 levels may assist in the evaluation and treatment of women with chronic pelvic pain.