Long-Term Survival Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Pseudomyxoma Peritonei: A 22-Year Single Institution Experience.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare condition, often associated with a poor prognosis if left untreated. Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC), have emerged as the preferred treatment for this condition. The aim of this study was to report 22-year single centre outcomes for PMP following CRS and HIPEC. METHODS: A retrospective analysis of a prospectively maintained database (CALHN reference number: Q20160412) from 2002-2024 was conducted on all patients that underwent CRS and HIPEC for PMP at The Queen Elizabeth Hospital, Adelaide, South Australia (TQEH). RESULTS: One hundred and twenty one CRS procedures were performed on 108 patients. Complete cytoreduction (CC0-1) was achieved in 85.9% cases. The overall median 3, 5 and 10-year survival rate for patients with PMP managed at TQEH was 70%, 55% and 23%, respectively. Among those who underwent HIPEC alongside CRS, the median survival was 92 months, with a 5-year survival rate of 62%. Median RFS was 109 months, with 61% 5-year RFS and 54% 10-year RFS. The 5-year survival rates for low-grade PMP and high-grade PMP without signet cells was 64.0% and 30.0%, respectively. CONCLUSION: CRS and HIPEC is a safe and effective treatment for patients with PMP, demonstrating a 62% survival at 5 years. High-grade PMP histology and CEA ≥ 5 were independent predictors of worse OS. Our results demonstrate that comparable survival rates and recurrence free intervals to those reported by high-volume centres can be achieved, reinforcing the potential for successful outcomes in lower-volume settings while maintaining treatment quality and patient safety.