Comparative Study of Short-Term Efficacy and Safety of Radical Surgery with or without Hyperthermic Intraperitoneal Chemotherapy in Colorectal Cancer with T4 Stage: A Propensity Score Matching Analysis

Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) in T4 colorectal cancer (CRC) remains controversial. The study aimed to explore the safety and efficacy of radical surgery (RS) with HIPEC in T4 CRC. Methods: Adverse events after HIPEC were estimated by Common Terminology Criteria for Adverse Events version 5.0. The efficacy was evaluated using recurrence-free survival (RFS) and overall survival (OS). Propensity score matching (PSM) was used to reduce the effects of confounders between groups. Results: Of the 417 patients (263 men and 154 women), 165 patients were treated with RS + HIPEC and 252 patients with RS alone. There was no significant difference in the incidence of all adverse events after PSM. Overall RFS and OS were not significantly different at 24 months (p = 0.580 and p = 0.072, respectively). However, in patients with T4b stage CRC (92.1% vs. 77.3%, p = 0.048) and tumor size ≥ 5 cm (93.0% vs. 80.9%, p = 0.029), RFS in the two groups showed a significant difference at 24 months. Conclusions: In summary, the safety of HIPEC in T4 CRC was confirmed. Compared with RS, though RS + HIPEC did not benefit the overall cohort at 24 months, RS + HIPEC could benefit patients with T4b stage CRC and tumor size ≥ 5 cm in RFS.