Complete cytoreductive surgery is the key to improving survival of colorectal cancer patients with peritoneal metastases: comment on PROPHYLOCHIP and PRODIGE 7

Abstract

Peritoneal carcinomatosis (PC) is one of the difficult problems in the treatment of colorectal cancer (CRC). Based on several retrospective analyses of large samples and prospective randomized controlled studies (RCTs), NCCN and PSOGI recommend cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for selected CRC patients with mild to moderate PC. There are two important controversial issues in this field: the survival benefit of second-look surgery plus HIPEC for the patients with high risk of PC, and the specific benefit of HIPEC added to CRS for patients with PC. PROPHYLOCHIP found that second-look surgery plus HIPEC in patients at high risk of PC does not result in increased survival. PRODIGE 7 showed that overall survival (OS, 41.7 months vs. 41.2 months, P=0.99) and recurrence-free survival (RFS, 13.1 months vs. 11.1 months, P=0.43) were similar between the HIPEC group and non-HIPEC group, and suggested that HIPEC is not necessary for patients who underwent complete CRS. However, due to a series of problems in the design and implementation of this trial, the conclusion has caused great controversy and has not been widely recognized. Through detailed analysis and in-depth discussion, we believe that the benefit of HIPEC could not be denied according to PRODIGE 7. CRS + HIPEC is the embodiment and model of the concept of "Solid tumor treatment is surgery-based integrated treatment". CRS is the cornerstone of therapeutic strategies with curative intent for CRC PC and complete CRS is the key to improve the prognosis. Furthermore, HIPEC is an effective supplement to CRS.