Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: outcomes from a national centre in the current era

Background Multimodal therapy incorporating cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival for selected patients with colorectal peritoneal metastases (CPMs). Many countries have centralised management of these patients, aiming to improve outcomes. There is ongoing debate on the need for and complications associated with HIPEC administration. We report indications and outcomes after CRS/HIPEC treated in a national centre in the modern era. Methods A retrospective review of all CPM patients who underwent CRS and HIPEC since the initiation of an Irish national program in 2013. The primary endpoint was the overall survival associated with CRS/HIPEC. Results During the study period (April 2013–June 2020), 123 patients proceeded to planned CRS/HIPEC for CPM. Median age was 58 (IQR 47–67) and 55 patients (44.7%) were male. In 65 patients (52.8%), CPM was synchronous. In 7/123 (5.8%), disease was unresectable. The median peritoneal cancer index (PCI) was 10 (IQR 5–17). Overall, 104/123 (84.5%) underwent a complete cytoreduction (CC0/CC1). Thirteen out of 123 (10.5%) patients also had a synchronous liver resection. Forty out of 123 (32.5%) patients had adverse pathological features (poorly differentiated or signet ring cells). The median survival in patients after CC0, CC1 and CC2/3 resection was 50, 18 and 11 months respectively (* p = < 0.0001, Log-rank Mantel-Cox). In total, 14/123(11.4%) had a major post-operative complication and 4/123 (3.3%) required re-operation. There was one (0.8%) post-operative death. The median length of stay was 14 days (IQR 9–19). Conclusion This study reports encouraging outcomes in patients with CPM undergoing CRS and HIPEC, especially when complete cytoreduction is achieved.