Prophylactic Hyperthermic Intraperitoneal Chemotherapy in Locally Advanced Colorectal Cancer: Systematic Review and Meta-Analysis.

BACKGROUND: Hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to be effective to treat peritoneal carcinomatosis (PM). However, the benefits of prophylactic HIPEC in patients with locally advanced colorectal cancer remains unknown. This meta-analysis aimed to determine the impact of prophylactic HIPEC in this setting. METHODS: We performed a systematic literature review using PubMed, Embase, and Web of Science databases according to pre-defined inclusion and exclusion criteria. Oncological parameters were extracted and pooled to analyze peritoneal metastasis-free survival, disease-free survival, and overall survival. RESULTS: We included 2023 patients (1470 in the control group and 553 in the prophylactic HIPEC group) originating from nine studies. One-year, 3-year, and 5-year peritoneal metastasis-free survival, 3-year and 5-year disease-free survival were better in the prophylactic HIPEC group than in the control group (hazard ratio [HR] 0.521, 95% confidence interval [CI] [0.292-0.930], P = 0.028; HR 0.333, 95% CI [0.152-0.731], P = 0.006; HR 0.334, 95% CI [0.125-0.887], P < 0.028; HR 0.701, 95% CI [0.574-0.855], P < 0.001; HR 0.714, 95% CI [0.590-0.864], P = 0.001), respectively. There was no statistically significant difference in overall survival, postoperative major complications, leakage, or surgical site complications between groups. CONCLUSIONS: While prophylactic HIPEC appears to improve peritoneal metastasis-free survival and disease-free survival, the findings should be interpreted cautiously and require confirmation through future high-quality randomized studies and collaborative individual patient data meta-analyses.