Novel prognostic score for outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal cancer with metachronous peritoneal carcinomatosis.

BACKGROUND: This study aimed to determine pre- and peri-operative parameters with significant predictive value for post-operative outcomes in patients with recurrent colorectal cancer presenting as peritoneal carcinomatosis undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), and to develop a novel prognostic scoring system for prediction of survival outcomes. METHODS: A single-institution review of prospectively collected data from all patients who underwent CRS-HIPEC between October 2005 and October 2017 was conducted. Univariate and multivariate analyses were used to identify significant parameters for prediction of post-CRS-HIPEC disease-free survival and overall survival (OS). RESULTS: A total of 278 patients underwent CRS-HIPEC, of whom 72 were for peritoneal carcinomatosis from recurrent colorectal cancer. Disease-free interval (DFI; P = 0.006), peritoneal cancer index (PCI; P = 0.001) and left upper quadrant disease (P = 0.023) were significant independent predictors of 3-year OS. DFI (0.007), PCI (P < 0.001) and intraoperative blood loss (BL; P = 0.001) were significant independent predictors of 5-year OS. PCI and BL were significant independent predictors of both 3-year (P = 0.026, PCI; P = 0.009, BL) and 5-year (P = 0.002, PCI; P = 0.011, BL) disease-free survival. Predictive models were developed for risk stratification of OS. CONCLUSION: PCI, DFI, left upper quadrant disease and BL have significant predictive value for post-CRS-HIPEC outcomes. Risk stratification models allow for more prudent patient selection and ultimately more accurate prognostication of post-operative outcomes.