Hyperthermic Intraperitoneal Chemotherapy Combined with Cytoreductive Surgery and Systemic Therapy Improves Prognosis in Colorectal Cancer with Peritoneal Metastases: An Updated Meta-Analysis.

INTRODUCTION

Patients with colorectal cancer (CRC) and peritoneal metastases (PMs) have a poor prognosis. The efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) remains controversial. This study aimed to evaluate the efficacy of HIPEC combined with cytoreductive surgery (CRS) and systemic therapy in these patients.

METHODS

PubMed, Web of Science, Embase, and the Cochrane Library were searched from their inception to March 2026. The primary outcomes were progression-free survival (PFS) and overall survival (OS). Treatment effects were quantified as pooled hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

This meta-analysis included 12 studies (2 randomized controlled trials), 9 cohort studies, and 1 case-control study), encompassing >2,700 patients. Pooled analysis showed that the addition of HIPEC significantly improved OS (HR = 0.60, 95% CI: [0.51, 0.70], p < 0.001, I2 = 18.2%), with a 40% reduction in mortality, and significant PFS benefit (HR = 0.51, 95% CI: [0.30, 0.87], p = 0.013, I2 = 76.3%), with a 49% reduction in the risk of progression or death. Subgroup analyses demonstrated consistent OS benefits across regions (Eastern: HR = 0.50, 95% CI: [0.32, 0.78]; Western: HR = 0.62, 95% CI: [0.52, 0.74]) and follow-up durations (<30 months: HR = 0.57, 95% CI: [0.51, 0.63]; ≥30 months: HR = 0.60, 95% CI: [0.42, 0.85]). No significant OS benefit was observed in either the peritoneal cancer index (PCI) <11 (HR = 0.71, p = 0.089) or PCI ≥ 11 (HR = 0.53, p = 0.063) subgroups. Regarding PFS, a significant benefit was observed only in patients with PCI < 11 (HR = 0.74, p = 0.043), whereas no significant difference was found in those with PCI ≥ 11 (HR = 0.45, p = 0.066).

CONCLUSION

HIPEC combined with CRS and systemic therapy significantly improves prognosis in patients with CRC and PM.