Effect of hospital volume on gastric cancer resection outcome in Switzerland: 24-year nationwide retrospective analysis.

Background
Postoperative mortality is a key indicator of surgical quality and central to volume-outcome research, which has shaped minimum case volume standards. In Switzerland, evidence for gastric cancer surgery outcomes remains limited, and regulation is still debated. This study analysed nationwide perioperative volume-outcome associations.Methods
The study comprised an analysis of the inpatient database from the Swiss Federal Statistical Office. Patients undergoing surgical or endoscopic resection for gastric cancer between 1998 and 2021 were included. Data were stratified by surgical caseload (quartiles), hospital inpatient volume, and hospital type. Outcomes included in-hospital mortality, failure to rescue, and perioperative morbidity.Results
Some 8708 patients from over 30 million hospital admissions were included. The annual resection volume increased from 290 in 2000 to 432 in 2020. The overall in-hospital mortality rate was 3.9%, with an inverse association with surgical caseload (2.2% in centres performing > 20 resections annually versus 2.8, 4.2, and 4.6% in lower-volume quartiles; P = 0.001). Similar correlations were observed for hospitals with > 35 000 inpatient admissions annually (2.3 versus 3.6 and 4.7%; P < 0.001) and for university hospitals (2.0 versus 4.2 and 4.3%; P < 0.001). Although the reported proportion of severe complications was higher, the rate of failure to rescue was lower in hospitals with high inpatient volumes (P < 0.001) and in university hospitals (P = 0.002).Conclusion
The findings of lower rates of in-hospital mortality and failure to rescue in hospitals with higher surgical and inpatient volumes support the potential value of centralization in gastric cancer surgery, and may guide future discussions on regulation.