Peritoneal cancer index as a predictor of survival in advanced stage serous epithelial ovarian cancer: a prospective study.

OBJECTIVE: A numerical score, the peritoneal cancer index (PCI), was developed to reflect the extent of tumor growth in gastric and colorectal cancers and to tailor treatment. This study aimed to examine the value of the PCI score in advanced epithelial ovarian cancer (EOC) regarding completeness of surgical cytoreduction and survival.

METHODS: This was a prospective observational cohort study. Patients with primary serous EOC at International Federation of Gynecology and Obstetrics (FIGO) stages IIIB or higher were included. Patients with FIGO stage IVB as well as those assigned to receive neoadjuvant treatment were excluded from the study. The PCI was obtained and registered intraoperatively.

RESULTS: In the study period we recruited 96 patients with serous EOC stage IIIB-IVA. A PCI score cut-off value of 13 was calculated using a receiver operator characteristic (ROC) curve, above which worse survival is expected (area under the curve [AUC]=0.641; 95% confidence interval [CI]=0.517-0.765; sensitivity and specificity 80.6%, 45.0%, respectively; p=0.050). A multivariate analysis determined that suboptimal surgical cytoreduction was the only independent predictive factor for recurrence (odds ratio [OR]=7.548; 95% CI=1.473-38.675; p=0.015). A multivariate analysis determined that only suboptimal surgical cytoreduction (hazard ratio [HR]=2.33; 95% CI=0.616-8.795; p=0.005), but not PCI score >13 (HR=1.289; 95% CI=0.329-5.046; p=0.716), was an independent predictive factor for death.

CONCLUSION: We conclude from this study that the PCI score is a reliable tool helping to assess the extent of disease in advanced serous EOC patients and may help predicting complete surgical cytoreduction but cannot qualify as a predictor of survival.