Hyperthermic intraperitoneal chemoperfusion with high dose oxaliplatin: Influence of perfusion temperature on postoperative outcome and survival [version 2; referees: 1 approved, 2 approved with reservations]

Introduction : Hyperthermic intraperitoneal chemotherapy (HIPEC) is becoming a standard therapy in the treatment of peritoneal carcinomatosis (PC). Compared to systemic chemotherapy, HIPEC improves survival in patients with PC. This therapy has high morbidity rates (up to 41%). In vitro it has been demonstrated that hyperthermia has a toxic effect on malign cells. However, hyperthermia also affects normal tissue. To my knowledge, any additional effect of hyperthermia combined with chemotherapy has never been demonstrated in a clinical setting. In this study, the effects of hyperthermia on outcome and survival were analyzed. Methods : Patients with PC from any origin who were treated with HIPEC were included in this retrospective, non-randomized study. Data on patient characteristics, tumor characteristics, features of the surgery and postoperative complications were extracted from patient files. Models predicting time to removal of nasogastric tube (TRNT), post-operative major complications, the occurrence of anastomotic leaks and post-operative survival were built, using negative binomial regression, logistic regression or Cox proportional hazards regression as appropriate. Results: 138 patients treated with HIPEC were included. Maximal temperature during the operation was not statistically significantly associated with anastomotic leaks or post-operative major complications. Maximal temperature during the operation was negatively associated with post-operative survival (P=0.01). Conclusion : The results suggest that hyperthermia may negatively affect survival in patients who are treated with HIPEC for PC of various origins. This study has the classical limitations of a retrospective study. Therefore, randomized trials are required to confirm the results.