The Management of Ovarian-Carcinoma Is Improved by the Use of Cancer-Associated Serum Antigen and Ca-125 Assays

Background. The new tumor‐associated mucin assay, cancer‐associated serum antigen (CASA), was assessed with the CA 125 assay for use in the management of patients with epithelial ovarian cancer. Methods. CASA and CA 125 were assessed retrospectively for use in (1) monitoring 28 patients with Stage 3 or 4 ovarian carcinoma during therapy, (2) predicting the outcome of 41 second‐look laparotomies (SLL), and (3) predicting the survival outcome by measuring these levels after surgery but before chemotherapy in 65 patients with Stage 3 disease. Results. Of 20 patients with recurrence after an initial response, the presence of CASA levels detected recurrence in 65% before clinical detection; CA 125, 50%; and the combination of CASA and CA 125, 80%. Six patients whose disease was in long‐term remission did not have elevations of either marker. When used to predict the results of SLL, the positive predictive values of CASA and CA 125 were 77% and 100%, respectively. The negative predictive values for CASA and CA 125 were 71% and 66%, respectively. CASA detected 50% of positive SLL where microscopic disease only was found; the CA 125 test did not. Multivariate analysis of survival rates using levels of CASA and CA 125, age, residual disease, tumor type and grade, or the presence or absence of cisplatin in the chemotherapeutic regimen found that postoperative CASA levels ranked above all prognostic factors except age. CASA levels may be more accurate than surgical reporting of residual disease or they may define a subset of patients with biologically more aggressive ovarian carcinoma. Conclusions. The CASA test is sensitive to ovarian carcinoma, and both CASA and CA 125 are more useful when used in conjunction