Correlation between peritoneal cancer index and survival in advanced epithelial ovarian cancer with complete resection

Objective The aim of this study was to investigate the relation between the peritoneal cancer index, overall survival, and recurrence free survival, in patients with epithelial ovarian cancer.Methods Patients treated at the Gustave-Roussy Institute between December 2004 and November 2017 for advanced epithelial ovarian cancer in complete resection were included. The correlation between the peritoneal cancer index and survival was studied using statistical modeling. Multivariate analysis was performed with a logistic regression model.Results Of the 351 patients included, 94 (27%) had initial surgery and 257 (73%) had interval surgery. Median follow-up was 52.7 months (range 47.6-63.9). Median peritoneal cancer index was 10 (range 0-32). The linear model best represented the relationship between peritoneal cancer index and overall survival. Patients with neoadjuvant chemotherapy had a greater instantaneous risk of baseline death than those with initial surgery, as well as a more rapid increase in this risk as the peritoneal cancer index increased. Overall survival and recurrence free survival were better in the initial surgery group (103.4 months (79.1-not reached (NR)) vs 66.5 months (59.1-95.3) and 31.8 months (23.7-48.7) vs 25.9 months (23.2-29), respectively). Risk factors for death were body mass index, peritoneal cancer index, and need for neoadjuvant chemotherapy.Conclusion The peritoneal cancer index is a prognostic indicator, but its linear relationship with survival precluded setting a unique peritoneal cancer index cut-off. Moreover, the prognostic impact of peritoneal cancer index was stronger in the setting of neoadjuvant chemotherapy.