Impact of extent of disease on 1‐year healthcare costs in patients who undergo cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: retrospective observational cohort study

BACKGROUND: The goal of this retrospective observational study was to determine the impact of the extent of peritoneal disease on 1‐year healthcare costs in patients with colorectal peritoneal metastases (PM) who undergo cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC). The extent of peritoneal disease, expressed by the Peritoneal Cancer Index (PCI), directly affects the complexity of CRS + HIPEC and ultimately survival outcomes. The impact of the PCI on treatment‐related healthcare costs remains unknown. METHODS: Data from patients with colorectal PM who underwent CRS + HIPEC between January 2012 and November 2017 were extracted retrospectively from an institutional database. Patients were divided into four subgroups with PCI scores ranging from 0 to 20. Treatment‐related costs up to 1 year after CRS + HIPEC were obtained from the financial department. Differences in costs and survival outcomes were compared using the χ (2) test and Kruskal−Wallis H test. RESULTS: Seventy‐three patients were included (PCI 0–5, 22 patients; PCI 6–10, 19 patients; PCI 11–15, 17 patients; PCI 16–20, 15 patients). Median (i.q.r.) costs were significantly increased for the PCI 11–15 and PCI 16–20 groups (€51 029 (42 500–58 575) and €46 548 (35 194–60 533) respectively) compared with those for the PCI 0–5 and PCI 6–10 groups (€33 856 (25 293–42 235) and €39 013 (30 519–51 334) respectively) (P = 0·009). CONCLUSION: Treatment‐related healthcare costs are significantly increased among patients with extensive tumour burden (PCI score 10 or above) who undergo CRS + HIPEC for the treatment of colorectal PM.