Recurrence of Colorectal Cancer With Peritoneal Metastases After Cytoreductive Surgery and HIPEC: A Retrospective Single-Center Cohort Study.

BACKGROUND

The efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer has recently been questioned. Two randomized, controlled trials, COLOPEC and PRODIGE 7, failed to demonstrate significant survival benefit of HIPEC over cytoreductive surgery alone, both using oxaliplatin as the intraperitoneal chemotherapeutic agent. This retrospective study aimed to assess the risk of colorectal cancer recurrence and overall survival following mitomycin C -based HIPEC.

METHODS

A retrospective analysis was conducted on 98 patients who underwent CRS with mitomycin C-based HIPEC for colorectal peritoneal carcinomatosis at Helsinki University Hospital between 2008 and 2023. Patients were followed until death or May 2025.

RESULTS

A total of 70 (71.4%) patients developed a recurrence during follow-up; the median time to recurrence was 0.69 (range: 0.10-3.49) years. The cumulative risk of recurrence was 43.4%, 65.1%, and 72.9% at 1, 2, and 3 years, respectively. A total of 41 (41.8%) patients died during follow-up, with 39 (95.1%) deaths due to recurrent colorectal cancer. For the entire cohort, the cumulative overall survival was 95.9%, 69.6% and 56.3% at 1, 3 and 5 years, respectively.

CONCLUSIONS

In this single-center retrospective study, the combination of CRS and HIPEC utilizing mitomycin C was correlated with positive long-term survival outcomes in selected patients with colorectal peritoneal carcinomatosis. Despite a high recurrence rate, over 50% of the patients were alive at 5 years. These findings suggest that mitomycin C may be a viable alternative to oxaliplatin in HIPEC protocols and support the continued use of this treatment approach in appropriately selected patients.