Cytoreductive surgery and HIPEC: A 10-year single-center retrospective cohort study

The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is widely used to treat pseudomyxoma peritonei (PMP), peritoneally metastasized colorectal or appendiceal cancer (pmCRC or pmAppCa) and peritoneal mesothelioma, although the specific efficacy of HIPEC remains inadequately proven. The aim of this retrospective study was to evaluate the outcomes of our CRS-HIPEC procedures and compare them with prior reports.

All patients operated with the intent of CRS-HIPEC at Oulu University Hospital (OUH) between September 2013 and August 2023 were prospectively registered in a CRS-specific quality control registry that included preoperative, intraoperative, and pathological data, as well as 30-day postoperative complications. The follow-up included thoracoabdominal computed tomography (CT) every 6 months for 3 years and after this yearly until 6 years postoperatively. Survival data were retrieved both from hospital records and from a national registry to analyze both short- and long-term outcomes of CRS-HIPEC.

Since its introduction at OUH in 2013, CRS-HIPEC was performed with curative intent in 272 patients. Peritoneal disease was confirmed in 223 (82%) cases. Among 171 resectable patients operated with CRS, 162 (95%) received HIPEC. Indications included pmCRC in 67 patients (41%), PMP in 61 (37%), pmAppCa in 23 (14%), and peritoneal mesothelioma in 7 (4%, other histology 4). Severe complications within 30 days (Clavien-Dindo class III-V) occurred in 68 patients (40%) of the CRS patients with a postoperative mortality of 0.6% (n = 1). The mean follow-up was 39 months (range 1-138). The estimated 5-year overall survival after CRS-HIPEC was 87% for PMP, 41% for pmCRC and 58% for pmAppCa. Estimated 5-year disease-free survival was 70%, 24%, and 36%, respectively.

CRS-HIPEC is associated with good OS and DFS in PMP, whereas survival after both pmCRC and pmAppCa is considerably lower. The procedure is associated with a considerable risk of severe complications and should therefore be performed in specialized centers only.