['CA 125 assays enable treatment response monitoring in ovarian cancer.', 'This multicentric study was carried out to assess the prognostic value of the CA 125 change after the first and the second courses of induction chemotherapy (CT). Of the 494 stage IIc-IV patients, 194 had a surgical second look, 397 (80.4%) relapsed and 382 (77.3%) died from cancer. Median (range) follow-up time was 34 months (3-215 months).', "In Cox models, CA 125 change after the first course (P < 0.0001), residual tumour (P = 0.003), CA 125 before the second course (P = 0.025) and patients' age (P = 0.048) were independent prognostic factors for overall survival (OS). A normal CA 125 before each of the two first CT courses or a CA 125 decrease >50% after the first course with a normal CA 125 before the second course identify patients with good prognosis. Both criteria retained a significant value in predicting second-look findings by univariate and multivariate analysis (P < 0.0001)."] Is change in CA 125 levels after the first cycle of induction chemotherapy an independent predictor of epithelial ovarian tumour outcome?