Mitomycin C-Based Hyperthermic Intraperitoneal Chemotherapy Improves Survival in Colorectal Cancer With Peritoneal Metastasis.

BACKGROUND: Colorectal cancer (CRC) with peritoneal metastasis is associated with poor prognosis despite advances in systemic chemotherapy and targeted therapies. Hyperthermic intraperitoneal chemotherapy (HIPEC) aims to eradicate free cancer cells within the peritoneal cavity and may improve survival outcomes. This study evaluated the efficacy and safety of mitomycin C (MMC)-based HIPEC in patients with CRC and isolated peritoneal metastasis. METHODS: Patients with CRC and peritoneal metastasis treated between November 2018 and January 2024 were retrospectively reviewed. Patients undergoing CRS followed by MMC-based HIPEC were compared with those managed without HIPEC. Clinicopathologic characteristics, perioperative outcomes, postoperative morbidity, and oncologic outcomes were analyzed. RESULTS: A total of 48 patients were included. The mean intraoperative Peritoneal Cancer Index was 9 (range, 2-33). Complete cytoreduction 0 was achieved in 29 patients (93.5%) who underwent CRS and HIPEC. Postoperative complications occurred in 10 patients (20.8%), with anastomotic leakage requiring reoperation in four patients (8.3%). Median overall survival was significantly longer in the HIPEC group compared with the non-HIPEC group (54.2 vs. 24.5 months, HR 0.30; 95% confidence interval [CI], 0.15-0.61; p < 0.001). The five-year overall survival rate was 47.9% in the HIPEC group vs. 4.9% in the non-HIPEC group. Median progression-free survival following HIPEC was 29.6 months (95% CI, 24.2-34.8). HIPEC was significantly associated with improved overall survival on multivariable analysis. CONCLUSION: CRS combined with MMC-based HIPEC provides a significant survival benefit for selected patients with colorectal cancer and isolated peritoneal metastasis. These findings support the role of MMC-based HIPEC as an effective locoregional treatment strategy.