Prophylactic Hyperthermic Intraperitoneal Chemotherapy in T4 Colorectal Cancer: Can it Improve the Oncologic Prognosis?

Introduction
Colorectal cancer (CRC) is a prevalent malignancy of the digestive system. Approximately 7% of CRC cases present with synchronous peritoneal metastases (PM), significantly reducing patient survival rates. The study aimed to determine if prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) could improve the prognosis for patients with T4 CRC.

Study Overview
This retrospective propensity score matching (PSM) cohort study included 220 patients with cT4N0-2M0 CRC treated at Zhejiang University School of Medicine between 2014 and 2018. The primary outcomes assessed were 3-year disease-free survival (DFS) and 3-year PM rate.

Methods
Patients were divided into two groups: those who received HIPEC (n = 45) and those who did not (n = 135). HIPEC was performed using either mitomycin C or oxaliplatin, administered through an extracorporeal circulation system at a constant temperature of 43°C for 60 minutes, either intraoperatively or within three days post-surgery.
Results

• 3-Year DFS: The HIPEC group demonstrated a significantly better 3-year DFS (83.9%) compared to the non-HIPEC group (67.2%).
• 3-Year PM Rate: The incidence of PM was significantly lower in the HIPEC group (2.2%) compared to the control group (11.1%).
• Subgroup Analysis: HIPEC improved DFS for T4N0-1M0 patients but not for T4N2M0 patients. Laparoscopic surgery followed by HIPEC did not increase the risk of PM.

Discussion
The findings suggest that prophylactic HIPEC may enhance the prognosis of patients with T4N0-1M0 CRC without significantly increasing surgery-related complications. However, HIPEC did not show a significant benefit for T4N2M0 patients, who have a higher propensity for distant metastasis. This highlights the importance of careful patient selection for HIPEC treatment.

Conclusion
Prophylactic HIPEC appears to provide significant benefits for certain CRC patients, particularly those with T4N0-1M0 staging. This treatment may lead to better long-term outcomes and lower recurrence rates, although further large-scale, randomized controlled trials are necessary to confirm these results and refine patient selection criteria.
DOI: 10.1016/j.ejso.2024.107958