Metabolic–Bariatric Surgery Reduces Pancreatic Cancer Risk: A Meta-Analysis of Over 3.7 Million Adults, Independent of Type 2 Diabetes Status

Abstract

Aims: To investigate the impact of Metabolic–Bariatric surgery (MBS) on pancreatic cancer (PCa) risk in individuals with obesity based on type 2 diabetes(T2D) status. Materials and Methods: We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines (PROSPERO: CRD42022367749). The primary outcomes were the PCa incidence rates in participants with or without T2D who underwent MBS compared with the control (non-MBS) group. Subgroup analyses based on the MBS types were performed and a random-effects model was employed. Sensitivity analysis was conducted by applying the leave-one-out meta-analysis technique and excluding studies with a short follow-up. Heterogeneity was evaluated using the I2 index and Cochran's Q test. Publication bias was assessed with Egger's test and the risk of bias was assessed with the Cochrane Risk-of-Bias tool. Results: Twelve studies, with 3,711,243 participants, were included. PCa risk was lower in the MBS group for both T2D and the overall population than in the non-MBS group (RR = 0.46, 95% CI: 0.30–0.71 and RR = 0.21; 95% CI: 0.07–0.57, respectively), with consistent findings after excluding studies with < 3-year follow-up. A favourable impact was also observed in individuals without T2D (RR = 0.56, 95% CI: 0.41–0.78). When comparing the types of MBS versus control, a significant difference was observed for sleeve gastrectomy (SG) (RR = 0.24; 95% CI, 0.12–0.46 for SG and RR = 0.52; 95% CI, 0.25–1.09 for Roux-En-Y bypass). Egger's test showed no indication of publication bias (p = 0.417). Conclusions: MBS is associated with reduced PCa risk regardless of T2D, with a more pronounced effect in T2D patients. Additional research is needed to investigate the impact of MBS types on PCa.