586P - The accuracy of the clinical PCI score in patients with peritoneal carcinomatosis of colorectal cancer

Abstract

BackgroundThe Peritoneal Cancer Index (PCI) and completeness of cytoreduction are important prognostic factors in patients with peritoneal carcinomatosis from colorectal cancer, undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). The PCI is determined during laparotomy by an experienced surgeon before the decision is made to ‘do’ or ‘do not’ proceed with CRS-HIPEC. The aim of this study is to determine the accuracy of the clinical PCI score (cPCI), by comparing the cPCI with the pathological PCI (pPCI) score. MethodsAll consecutive patients who underwent CRS-HIPEC for peritoneal carcinomatosis from colorectal origin between February 2015 and June 2018 where identified. Relevant patient- and tumor related characteristics were collected. ResultsIn total 119 patients were included in this study; 60 males (50.4%). Median age was 64 years [IQR 55-71]. The pPCI was lower than the cPCI score in 80 patients (67.2%), the score was equal in 38 patients (31.9%), and in 1 patient (0.8%) the pPCI was higher than the cPCI. The median total cPCI 11 (IQR 6-16) was significantly higher than the median pPCI, (pPCI=8, IQR 3-13, p<0.001). In 21 patients (17.6%) the cPCI was overestimated ≥5 points. When patients were divided in different PCI categories, 0-5, 6-10, 11-15, ≥16 respectively, 39 patients (32.8%) moved to a lower pPCI category with corresponding better median survival rates. ConclusionsClinical determination of the PCI often results in overestimation of the score. Far-reaching consequences are tied to the macroscopic evaluation of the cPCI by the surgeon, but this evaluation is not very reliable. Further research is warranted to determine whether the pPCI is a better scoring method/more precise prognostic factor for oncological outcomes after CRS-HIPEC. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.