Should CA-125 response criteria be preferred to response evaluation criteria in solid tumors (RECIST) for prognostication during second-line chemotherapy of ovarian carcinoma?

Purpose The aim of the study was to compare the prognostic value of a response by the Gynecologic Cancer Intergroup (GCIG) Cancer Antigen (CA) -125 response criteria and the Response Evaluation Criteria in Solid Tumors (RECIST) on survival in patients with ovarian carcinoma receiving second-line chemotherapy. Patients and Methods From a single-institution registry of 527 consecutive patients with primary ovarian carcinoma, 131 records satisfied the inclusion criteria: ovarian carcinoma of International Federation of Gynecology and Obstetrics stage IC to IV, first-line chemotherapy with paclitaxel and a platinum compound, refractory or recurrent disease, and second-line chemotherapy consisting of topotecan or paclitaxel plus carboplatin. Univariate and multivariate analyses of survival were performed using the landmark method. Results In patients with measurable disease by RECIST and with assessable disease by the CA-125 criteria (n = 68), the CA-125 criteria were 2.6 times better than the RECIST at disclosing survival. In a multivariate Cox analysis with inclusion of nine potential prognostic parameters, CA-125 response (responders v nonresponders; hazard ratio, 0.21; P <.001) and number of relapse sites (solitary v multiple; hazard ratio, 0.47; P = .020) were identified as contributory prognostic factors for survival, whereas the parameters of RECIST (responders v nonresponders), as well as the remaining variables, had nonsignificant prognostic impact. Conclusion The GCIG CA-125 response criteria are a better prognostic tool than RECIST in second-line treatment with topotecan or paclitaxel plus carboplatin in patients with ovarian carcinoma.