Abstract:【Abstract】 Objective TO investigate the correlation between preoperative platelettolymphocyte ratio (PLR) and optimal debulking surgery (ODS)in ovarian cancer (OC).Methods Clinicopathological data of 228 OC patients whose initial treatment were surgical treatment and underwent surgical resection in the Second Clinical Medical School of North Sichuan Medical College from May 2007 to May 2017 were analyzed. The clinicopathological characteristics of two groups of OC patients with suboptimal debulking surgery (SODS) and ODS were analyzed by chisquare test or t test. Univariate and multivariate analyses were performed to evaluate the clinical factors affecting ODS with binary logistic regression. The receiver operating characteristic (ROC) curve of PLR predicting ODS in OC was drawn. The optimal cutoff value of PLR predicting ODS of patients with OC was determined by ROC curve, and the OC patients were categorized into two group according to the optimal cutoff value of PLR. The overall survival (OS) of the 2 groups patients were compared statistically.Results Of 228 OC patients, 105 cases were underwent ODS, and 123 were underwent SODS. PLR,serum CA125,malignant ascites were valuable factors to predict ODS in OC(P=0021,P=0007,P<00001).According to the ROC curve of PLR predicting ODS, the optimal cutoff value of PLR predicting ODS in OC patients was 182. Accordingly, all the 228 OC patients were categorized into the high PLR group (PLR>182, n=103) and low PLR group (PLR≤182, n=125). The OS patients of low PLR group was 70 months, which was obviously longer than that of high PLR group 39 months, and the difference was statistically significant(χ2=31387,P<00001).Conclusion As one of preoperative inflammatory index in peripheral blood, the preoperative PLR is related to the ODS of OC.PLR can be used as a predictive factor for ODS in the initial treatment of OC.