Oncological outcomes and hospitalization cost of hyperthermic intraperitoneal chemotherapy (HIPEC) open and closed abdomen techniques: Results from two French expert centers.

Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) associated with CC0 excision is performed using either an open (OPEN_HIPEC) or closed abdominal technique (CLOSED_HIPEC). However, little data is available on the costs of this treatment, as there is no code for HIPEC in the French Classification of Medical Acts. Oncological outcomes and the mean cost of hospitalization were compared.

Methods: Between 2017 and 2021, 144 patients with peritoneal carcinomatosis (all etiologies) were included (OPEN_HIPEC, n = 70; CLOSED_HIPEC, n = 74) in this retrospective two-center study. Morbi-mortality, overall survival (OS), recurrence-free-survival (RFS) and mean cost of hospitalization were compared.

Results: The median OS and RFS were 71.3 months [63-71.5] and 26.8 months [20-35.3] respectively, and were similar for both techniques; and after stratification by histology. Multivariate analysis adjusted on PCI score of OS identified mitomycin as a protective factor (HR = 0.31 [0.10-0.90], p = 0.032) and ASA score>2 (HR = 2.32 [1.32- 4.06], p = 0.003) and number of resection (HR = 1.21 [1.06-1.39], p = 0.006) as a risk factors of RFS. Complication rates at day 30 were similar between OPEN and CLOSED_HIPEC, 31 (44.3 %) vs 42 (56.8 %); p = 0.135. OPEN_HIPEC had more severe complications (11 (35.5 %) vs 6 (14.3 %); p = 0.034). The mean cost of hospitalization was estimated as €15,627 for OPEN_HIPEC and €14,211 for CLOSED_HIPEC for a mean length-of-stay of 12.7 and 16.7 days respectively. The mean amount received by the hospital per hospitalization was estimated at €16,399 and €15,536 respectively.

Conclusions: OS and RFS were similar for open and closed HIPEC. Severe complications at day 30 were more frequent in OPEN_HIPEC group. The amount received by hospital for both HIPEC techniques is sufficient.