Specificity of Procedure Volume and its Association With Postoperative Mortality in Digestive Cancer Surgery: A Nationwide Study of 225,752 Patients

OBJECTIVES: We aimed to examine whether the improved outcome of a digestive cancer procedure in high-volume hospitals is specific or correlates with that of other digestive cancer procedures, and determine if the discriminant cut-off of hospital volume may influence postoperative mortality (POM) regardless of the procedure. BACKGROUND: Performing complex surgeries in tertiary centers is associated with improved outcome. However, the association between POM and hospital volume of nonspecific procedures is unknown. METHODS: Patients who underwent colectomy, proctectomy, esophagectomy, gastrectomy, pancreatectomy, and hepatectomy for cancer between 2012 and 2017 were identified in the French nationwide database. Chi-square automatic interaction detector was used to identify the cut-off values of the annual caseload affecting the 90-day POM. A common threshold was estimated by minimization of chi-square distance taking into account the specific mortality of each procedure. RESULTS: Overall, 225,752 patients were identified. Hospitals were categorized according to the procedure volume (colectomy: ≥80 cases/yr, proctectomy: ≥35/yr, esophagectomy: ≥41/yr, gastrectomy: ≥16/yr, pancreatectomy: ≥26/yr, and hepatectomy: ≥76/yr). The overall 90-day POM was 5.1% and varied significantly with volume. The benefits of high volume were transferable across procedures. High-volume hospitals for colorectal cancer surgery significantly influenced the risk of death after hepatectomy (P < 0.001) and pancreatectomy (P < 0.001). The common threshold for all procedures that influenced POM was 199 cases/yr (odds ratio 1.29, P < 0.001). CONCLUSION: In digestive cancer surgery, the volume-POM relationship of one procedure was associated with the volume of other procedures. Thus, tertiary hospitals should be defined according to the common threshold of different procedures.