1015 Linear relationship of peritoneal cancer index and survival in patients with epithelial ovarian cancer in carcinomatosis

Introduction/Background* The aim of this study was to investigate the relation between the PCI and overall survival (OS) and recurrence-free survival (RFS). The peritoneal cancer index (PCI) is one of the main prognostic factor for the evaluation of ovarian peritoneal carcinosis. Different thresholds have been reported in terms of prognosis and to help in the decision between chemotherapy or primary surgery, but no consensus was found. Methodology Patients treated at Gustave Roussy between 2004 and 2017 for advanced epitoneal ovarian cancer in complete resection were included. The correlation between PCI and survival was studied using statistical modeling. Multivariate analysis was performed by a logistic regression model. Result(s)* Of the 351 patients included, 27% had initial surgery, 73% had interval surgery. The median follow-up was 52.7 months. The mean PCI was 10.8 (0-32). The linear model best represented the relationship between PCI and OS. 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 PCI increased. OS and PFS were better in the initial surgery group (103.4 months [79.1-NA] 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 BMI, PCI and performance of neoadjuvant chemotherapy. Conclusion* PCI is a major prognostic element but its linear relationship with survival does not allow us to establish a cut-off. Moreover, the prognostic impact of PCI is even stronger in the case of primary chemotherapy.