An independent evaluation of the potential clinical usefulness of proposed CA-125 indices previously shown to be of prognostic significance in epithelial ovarian cancer.

CA-125 levels were assessed prior to each of the first three cycles of chemotherapy, in 81 patients with epithelial ovarian cancer receiving first-line chemotherapy. All patients have at least 1 year's follow-up. Thirty-nine patients (48%) have progressed clinically or have died within 1 year of treatment (treatment 'failures'). Three CA-125 indices previously shown to be of prognostic value are assessed for their ability to pick-out these 'failures'. When the indices examined are modified to obtain a specificity for picking out failures just exceeding 90%, the maximum sensitivity obtained was 46%. The use of CA-125 for clinical decision making in ovarian cancer requires further investigation to determine and validate a prognostic index with acceptable sensitivity and specificity, and to determine the clinical impact of treatment decisions made using such an index.