Long term survival in patients with peritoneal metastasised gastric cancer treated with cytoreductive surgery and HIPEC: A multi-institutional cohort from PSOGI

Background: Peritoneal metastasis (PM) of gastric cancer (GC) is relatively common (17%) and is associated with poor survival. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is still controversially discussed, as it has proven an increase in survival in selected patients, but only a small subgroup reached long-term survival. The aim of this study was to collect and analyse a worldwide cohort of patients treated with CRS and HIPEC with long-term survival in order to explore relevant patient characteristics. Methods: We conducted a questionnaire, which was distributed to all collaborators of the Peritoneal Surface Oncology Group International (PSOGI). Inclusion criteria were: histopathologic proven PM of GC, treated with CRS and HIPEC, and overall survival >5 years. Patient, tumour, and therapeutic details were collected and analysed. Results: From an analysis of 448 patients treated between 1994 and 2014, a total of 28 patients with a mean age of 53.0 years and mean PCI of 3.3 were included. The overall median survival was 11.0 years (min 5.0; max 27.9). The predictors completeness of cytoreduction (CC-0) and PCI<6 were present in 22/ 28 patients. 12/28 patients developed at a median of 9.6 years tumour recurrence, and was associated with inferior median overall survival compared to patients without recurrence (8.8 years vs. not reached; p = 0.002). Conclusions: Long-term survival and even cure are possible in patients with PM of GC treated with CRS and HIPEC. Completeness of cytoreduction and low PCI seemed to be crucial. Further studies are needed in order to improve existing selection criteria. (C) 2020 Published by Elsevier Ltd.