Comparative study of the short-term outcomes of gastric cancer surgery between Japanese Gastric cancer association-certified and non-certified institutions: a retrospective cohort analysis using a national database in Japan

BACKGROUND: This study assessed the impact of an institutional certification system that was newly introduced by the Japanese Gastric Cancer Association on short-term surgical outcomes in patients with gastric cancer using data from the National Clinical Database. METHODS: A retrospective cohort study of distal gastrectomy and total gastrectomy procedures performed between January 2020 and December 2022 was conducted. The institutions were classified into three categories: type A, type B, and non-certified institutions, in decreasing order of certification stringency. The primary outcome was the incidence of grade ≥ IIIa postoperative complications based on the Clavien-Dindo classification system. The secondary outcome was surgery-related mortality. Logistic regression with risk adjustment, estimated using generalized estimating equations, was used to account for intra-cluster correlation. RESULTS: There was no significant difference in the risks of distal gastrectomy-related complications across the three institution types. However, type A- (odds ratio (OR) 0.39, 95% confidence interval (CI) 0.31-0.49) and type B-certified institutions (OR 0.59, 95% CI 0.49-0.71) had a significantly lower mortality risk than non-certified ones. On the other hand, Type A- (OR 1.25, 95% CI 1.09-1.44) and type B-certified institutions (OR 1.17, 95% CI 1.03-1.33) had higher risks of postoperative total gastrectomy-related complications than non-certified ones. Nevertheless, type A- (OR 0.41, 95% CI 0.29-0.58) and type B-certified institutions (OR 0.67, 95% CI 0.51-0.88) had significantly lower surgery-related mortality risks than non-certified ones. CONCLUSIONS: Certified institutions demonstrated lower surgical mortality risks, highlighting the benefits of the certification system and the importance of institutional quality.