Effect of the learning curve of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) on the treatment of colorectal peritoneal metastasis

Summary: Background: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) are increasingly utilised in the management of colorectal peritoneal metastases (CPM). This combined modality is associated with a significant learning curve (LC) and is often criticised for its associated morbidity. This study aims to inspect the LC of this procedure in our institute. Methods: A retrospective review of the institution's prospectively maintained database of CRS-HIPEC cases was performed. Patients treated for CPM were stratified into two groups: Group 1 consists of patients in our initial 100 cases of CRS-HIPEC and Group 2 comprises patients treated subsequently. Perioperative prognostic factors and oncological outcomes were analysed. Results: Between 2001 and 2016, 77 patients with CPM underwent CRS-HIPEC, of which 31 patients (40.3%) were in Group 1 and 46 patients (59.7%) in Group 2. Median follow-up duration was 96 months in Group 1 and 25 months in Group 2. There were no differences in OS (35 months vs 46 months, p = 0.054) and DFS (13 months vs 14 months, p = 0.676) between the groups. There were more patients with higher PCI (≥12) (57.1% vs 22.2%, p = 0.006) and high-grade complications (25.8% vs 8.7%, p = 0.045) in Group 1. Group 2 patients had a shorter hospitalisation (14 days vs 11 days, p = 0.015) and SICU stay (1 day vs 0 days, p