Prognostic Value of Peritoneal Cancer Index After Complete Cytoreductive Surgery in Advanced Ovarian Cancer

Background/aim: Residual disease (RD) after primary debulking surgery (PDS) is a prognostic factor for survival in advanced ovarian cancer (AOC). This study aimed to examine whether the tumor extent affects overall survival (OS) and progression-free survival (PFS) in AOC patients treated with PDS.
Patients and methods: A total of 118 patients treated with PDS were included. Age, ECOG score, AOC International Federation of Gynecology and Obstetrics (FIGO) stage, CA-125, RD, peritoneal cancer index (PCI), preoperative imaging (CT-PCI) and macroscopic visualization at the surgery start (S-PCI) were analyzed. Tumor extent was quantified using the PCI, and by CT-PCI and S-PCI. Cox regression, Kaplan-Meier and receiver operating curves (ROC) were performed for survival analyses.
Results: S-PCI correlated with both OS (1.067, 95%CI=1.018-1.119, p<0.007) and PFS. Patients exhibiting S-PCI≥18.5, adjusted to age, performance status, and RD, had a two-fold risk of dying (HR=2.070, 95%CI=1.061-4.038, p=0.033) compared those with PCI<18.5. CT-PCI correlated with OS in crude data (1.037, 95%CI=1.005-1.071, p=0.025), but this was not sustained in multivariate analyses. RD of any size doubled the risk of dying (2.177, 95%CI=1.235-3.838, p=0.007).
Conclusion: The tumor extent at the beginning of surgery seemed to affect OS in patients with AOC, regardless of the extent of RD at the end of the surgery. PCI above 18.5 doubled the risk of dying of the disease. No difference in major complications was noted in the two groups of patients. CT-PCI seemed to play a prognostic role for PFS; however, it is still to be investigated as a prognostic factor for OS.