Primary curative surgery and preemptive or adjuvant hyperthermic peritoneal chemotherapy in colorectal cancer patients at high risk to develop peritoneal carcinomatosis. A systematic review.

Purpose: To evaluate all available data on the effect of preemptive intervention in patients who have curative surgery for colorectal cancer (CRC) and are at high risk to develop peritoneal carcinomatosis (PC). Methods: The authors conducted a systematic review of all published studies from January 2000 to July 2016. Twelve studies were eventually considered for analysis, and were divided in four categories, according to different approaches for adjuvant intra-peritoneal chemotherapy: a) hyperthermic intraperitoneal chemotherapy (HIPEC), during primary surgery for CRC; b) early postoperative intraperitoneal chemotherapy (EPIC), after primary surgery for CRC; c) early reintervention (laparotomy or laparoscopy) and HIPEC; and d) as second look laparotomy and HIPEC + cytoreductive surgery (CRS), several months after primary surgery. Results: Considering prophylactic HIPEC during primary surgery, the studies that were analysed showed a peritoneal recurrence rate of 0-12.9%, a 3- and 5-year disease free survival (DFS) of 67-97.5% and 54.8-84% respectively, and a 3- and 5-year overall survival (OS) of 67-100% and 84%, respectively. These oncological results are probably better than what is expected in patients at high risk to develop PC and have only adjuvant systemic chemotherapy. Because of the great heterogeneity in inclusion criteria (risk factors for PC) and methodology of intra-peritoneal chemotherapy (different timing, different techniques, different agents), a meta-analysis was not performed. Conclusions: At present and because of the insufficient available evidence, preemptive intervention at the immediate postoperative adjuvant setting is recommended only in the setting of a registered clinical trial.