Survival and morbidity in elderly patients treated with cytoreductive surgery and HIPEC for colorectal peritoneal metastases: a population-based study.

[OBJECTIVE] Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) has improved outcomes in colorectal cancer (CRC) patients with peritoneal metastases (PM), yet evidence regarding perioperative risk and long-term survival in those 75 years or older remains uncertain. The aim of this study was to evaluate whether age ≥75 years impacts on overall survival (OS) and postoperative in-hospital morbidity, according to Clavien-Dindo classification (CD), compared with patients aged <75 years.

[METHOD] This population-based study collected data from the National Swedish HIPEC Registry, including patients with colorectal PM operated with CRS-HIPEC. Patients were stratified by age (≤74 vs ≥75) with OS as primary outcome. Secondary outcomes were in-hospital mortality, postoperative morbidity and disease free survival (DFS). Potential variables assessed for association with OS were Complete Cytoreduction Score (CCS), Peritoneal Carcinomatosis Index (PCI) score, p/ypN stage of the primary tumor, postoperative morbidity and age.

[RESULTS] A total of 592 patients were operated between 2004 and 2021, of which 553 were ≤74 years and 39 were ≥75 years. OS did not differ between age groups ( = .951). Factors affecting OS negatively were high CCS ( = .004), PCI ≥21 ( = .009) and p/ypN2 ( = .041). No difference was observed in DFS ( = .525). The rate of CD grade III-IV was 27% in patients ≤74 years and 21% in patients ≥75 years ( = .495). The in-hospital mortality rate was 1.3% in patients ≤74 and none in patients ≥75 years. Reoperation rates were similar between groups.

[CONCLUSION] These results indicate that age above 74 should not automatically exclude patients from undergoing CRS-HIPEC. Careful selection ensures favorable survival without an increase in postoperative morbidity.