The Relationship Between Bariatric Surgery and Gallbladder Cancer (GBC): A Systematic Review and Meta-analysis

Recent studies suggest bariatric surgery might protect against gallbladder cancer (GBC), but evidence is inconclusive. We conducted a meta-analysis of cohort studies identified through PubMed, Embase, and Cochrane Library. Random-effects models generated pooled risk ratios (RR) with 95% confidence intervals (CI), and heterogeneity was assessed with Cochran's Q and I². Ten cohort studies totaling 3,929,395 participants were included. Bariatric surgery was associated with a significantly lower incidence of GBC (95% CI = 0.35-0.90), with moderate heterogeneity (P = 0.014; I²=56.5%). Leave-one-out sensitivity analyses confirmed robustness. In the subgroup analyses by the size of the surgical sample, the pooled HR was 0.45 (95% CI = 0.28-0.74) for less than 50,000. In the subgroup analyses by analysis method, the pooled HR was 0.48 (95% CI = 0.25-0.94) for Univariate analysis. Moreover, in studies with Newcastle-Ottawa Scale(NOS), HR was 0.6 (95% CI = 0.43-0.83) for more than 6 points. Overall, bariatric surgery may reduce GBC risk, but effects vary by region, sample size, confounding adjustment, and study quality. KEY POINTS: • Bariatric surgery is associated with a reduced risk of GBC in people living with obesity. • The protective association is more evident in specific subgroups and remains robust across sensitivity analyses. • Larger, long-term RCTs are required to confrm benefts.