Serum CA 125 levels in preoperative evaluation of pelvic masses.

Serum CA 125 levels in 182 gynecology patients with pelvic masses were measured preoperatively. We found values exceeding 35 U/mL in 14 of 18 patients (77.8%) with malignant pelvic tumors. Thirty-six of 164 benign pelvic masses (22%) were associated with CA 125 levels above 35 U/mL, and 19 of 164 (11.5%) had levels that exceeded 65 U/mL. The degree of CA 125 elevation did not correlate with lesion size or weight. Elevated levels were often associated with benign secondary pathology such as endometriosis. Incorporating an age cutoff arbitrarily set at 50 years helped to interpret an elevated CA 125 level. Our findings suggest that an elevated serum CA 125 level by itself does not sufficiently distinguish benign from malignant masses preoperatively.