Oxaliplatin versus Mitomycin C for HIPEC in colorectal cancer peritoneal carcinomatosis

Objective Compare long-term outcomes in colorectal cancer (CRC) patients with peritoneal carcinomatosis (PC) treated with peritonectomy/HIPEC using oxaliplatin versus MMC. Background Peritonectomy and heated intraperitoneal chemotherapy (HIPEC) greatly improves patient survival in CRC PC. This procedure is not uniform across centres and the optimal choice of HIPEC chemotherapeutic is unclear. Oxaliplatin and Mitomycin C (MMC) are the most commonly used agents and comparative studies have reported varying results. Method 201 patients were retrospectively selected from the St George Hospital database, all of which had undergone peritonectomy/HIPEC for CRC PC. Oxaliplatin and MMC were used in 106 and 96 patients, respectively. Each patient's baseline characteristics, operative details, choice of chemotherapeutic agent and survival were noted. Results The two groups did not differ significantly at baseline. Patients receiving oxaliplatin had significantly greater unadjusted median survival compared to MMC (56.0 ± 8.1 vs. 29.0 ± 3.4 months) which translated into a hazards ratio of 0.59 (95% CI 0.37–0.91, p = 0.017). Subgroup analysis further confirmed an advantage with oxaliplatin in females, moderate-well differentiated tumours, tumours without signet ring pathology and PCI 10–15. Conclusion Our study suggests oxaliplatin offers a survival advantage over MMC when used for HIPEC in CRC PC. Further studies to understand its efficacy, complications and ideal preparation are required. A Phase III randomised control trial comparing oxaliplatin and MMC would enhance decision-making.