Association between hospital volume and mortality after elective oesophageal cancer resection in Switzerland: A retrospective national registry study from 2013 to 2022

Purpose: The association between a high annual hospital-specific case volume and improved postoperative outcomes after oesophageal cancer resection (OCR) is well described. The Swiss government started centralisation of OCR in 2013. This study investigates this centralisation in terms of the annual hospital-specific case volume of OCR (hospital volume) and its effect on short-term postoperative outcomes. Methods: National inpatient registry data of all hospitals providing OCR (ICD codes C15 and at least one of the CHOP codes starting with 424, 425, or 426) between 2013 and 2022 in Switzerland were analysed. The primary endpoint was in-hospital mortality. Secondar endpoints were postoperative complications and length of hospital stay (LOS). Additional objectives were sociodemographic time trends. Results: 1’535 cases were identified. The annual number of hospitals providing OCR ranged between 30 in 2013 and 14 in 2021. Hospital volume varied between one and 40 patients per year. Overall mortality was 5.3% (n=81) declining from 9.3% in 2013 to 3.8% in 2022 (t=-0.511, p=0.040). Increasing hospital volume was associated with lower risk for mortality (odds ratio (OR)=0.723, 95% confidence interval (CI) 0.53 to 0.98, p=0.037) and postoperative complications (OR=0.705, 95%CI: 0.62 to 0.83, p<0.001), and shorter LOS from the 8th quantile of LOS upwards (p<0.001). Conclusions: A higher hospital volume is associated with reduced mortality and postoperative complications. The ongoing centralisation of OCR in Switzerland must be further advanced in order to enhance clinical outcomes, ensure patient safety, and be able to compare nationally with international benchmark centres. Clinical trial registration ClinicalTrials.gov, NCT07022652, https://clinicaltrials.gov/search?id=NCT07022652