Prognostic impact of cytoreductive surgery conducted with primary intent, versus cytoreductive surgery after neoadjuvant chemotherapy, in the management of patients with advanced epithelial ovarian cancers: a multicentre, propensity score‐matched study from the <scp>FRANCOGYN</scp> group

International audience; Objective: To compare survival and morbidity rates between primary cytoreductive surgery (pCRS) and interval cytoreductive surgery (iCRS) for epithelial ovarian cancer (EOC), using a propensity score.Design: We conducted a propensity score-matched cohort study, using data from the FRANCOGYN cohort.Setting: Retrospective, multicentre study of data from patients followed in 15 French department specialized in the treatment of ovarian cancer.Sample: Patients included were those with International Federation of Gynaecology and Obstetrics (FIGO) stage III or IV EOC, with peritoneal carcinomatosis, having undergone CRS.Methods: The propensity score was designed using pre-therapeutic variables associated with both treatment allocation and overall survival (OS).Main outcome measures: The primary outcome was OS. Secondary outcomes included recurrence-free survival (RFS), quality of CRS and other variables related to surgical morbidity.Results: A total of 513 patients were included. Among these, 334 could be matched, forming 167 pairs. No difference in OS was found (hazard ratio, HR = 0.8, p = 0.32). There was also no difference in RFS (median = 26 months in both groups) nor in the rate of CRS leaving no macroscopic residual disease (pCRS 85%, iCRS 81.4%, p = 0.76). The rates of gastrointestinal tract resections, stoma, postoperative complications and hospital stay were significantly higher in the pCRS group.Conclusions: Analysis of groups of patients made comparable by propensity score matching showed no difference in survival, but lower postoperative morbidity in patients treated with iCRS.