The management of patients with colorectal cancer (CRC) with peritoneal metastases is challenging, and the roles of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are unclear and debated among experts.
The experts of the Swiss Peritoneal Cancer Group were contacted and agreed to participate in this analysis. Experts from 9 centers in Switzerland provided their decision algorithms for CRS/HIPEC for patients with or at high risk for peritoneal metastases from CRC. Their responses were converted into decision trees on the basis of objective consensus methodology. The decision trees were used as a basis to identify consensus and discrepancies.
The final treatment algorithms included a total of 5 decision criteria (age, Peritoneal Cancer Index [PCI], extraperitoneal metastases, Peritoneal Surface Disease Severity Score, and various risk factors [RF]) and 2 treatment options (HIPEC, yes or no). HIPEC was never recommended for patients without peritoneal metastases in the absence of RF for peritoneal metastases. For patients with a PCI ≤15 without organ metastases, all centers recommended CRS/HIPEC. There was also a consensus not to perform CRS/HIPEC in elderly patients (80 years and older), those with a PCI >20, and those with unresectable metastases. For patients with a PCI = 16 to 20, there was no consensus.
Multiple decision criteria relevant to all participating centers were identified. Because patient selection for CRS/HIPEC remains difficult, uniform criteria for the term "high risk" for peritoneal metastases and systemic metastases are helpful. Future trials and guidelines should take these criteria into account.