Variation in the peritoneal cancer index scores between surgeons and according to when they are determined (before or after cytoreductive surgery)

Introduction: The prognosis of peritoneal carcinomatosis (PC) is highly dependent on the extent of the PC. This extent is calculated by the peritoneal cancer index (PCI). In the future, the indications for complete cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) should be partially based on the PCI. This raises the question of the concordance between the PCI scores calculated by different surgeons, and a possible variation before and after CRS. Objective: To analyze variations in the PCI score between surgeons and according to when it is determined (before and after surgery). Patients and methods: Prospective recording of the PCI score independently calculated by senior and junior surgeons, before CRS (when the surgeon decided to perform this procedure), and after CRS, in 75 consecutive patients. A concordance analysis was conducted. Results: The origins of the PC were colorectal (n = 38), pseudomyxoma (n = 22), mesothelioma (n = 8) and miscellaneous lesions (n = 7). Concordance between the PCI score was very high (close to 90%) among the senior surgeons and junior surgeons before and after CRS. After CRS, the mean PCI score increased by 1.75 (IC-95%: 2.09-1.41). This high concordance was similar whatever the level of the PCI score and whatever the origin of the tumor. Conclusion: The PCI is a reliable tool for measuring the extent of PC. It is easy to use and inter-surgeon concordance is high. It increases by approximately 2 before and after CRS.