Tumor Load Matters - the Peritoneal Cancer Index in Patients With High-grade Serous Ovarian Cancer

The aim of this study was to analyze the predictive and prognostic value of the peritoneal cancer index (PCI) with regard to complete cytoreduction and clinical outcomes in patients with high-grade serous ovarian cancer.

In a cohort comprising 188 patients with high-grade serous ovarian cancer, the PCI was retrospectively assessed. Clinical factors and perioperative complications were analyzed according to different PCI groups. Five-year disease-free survival (DFS) and overall survival (OS) were calculated based on the Kaplan-Meier Log rank analysis. Receiver operating characteristic (ROC) analysis was applied to detect associations of PCI and complete cytoreduction. Multivariate survival analysis was performed by Cox proportional hazards model.

In our study, the PCI was predictive of complete cytoreduction (ROC analysis; AUC 0.8227). In patients with optimal cytoreduction, higher PCI scores were associated with poorer 5-year OS (p<0.001) and 5-year DFS (p<0.001). Complications (G1-G5) were significantly more frequent in patients with PCI scores >9 (p=0.0023). Five-year OS was reduced in patients with severe complications compared to patients with none or mild complications (30.88% versus 51.01%; p=0.001). There were significant OS (p<0.001) and DFS (p<0.001) differences between patients with none or mild versus severe complications following complete cytoreduction within the PCI subgroups (PCI: 9-11, PCI: 12-18, PCI >18).

The PCI score showed high predictability for complete cytoreduction and was associated with clinical outcomes. In presence of severe complications, higher PCI scores were associated with poorer survival. Hence, in patients with high tumor load, the prevention of severe perioperative complications is of utmost importance in all cases where complete cytoreduction is deemed to be feasible.