An updated systematic review, meta-analysis, and network meta-analysis of breast cancer incidence after metabolic and bariatric surgery
摘要
Obesity is associated with breast cancer risk, and metabolic bariatric surgery (MBS) may reduce obesity-related cancer incidence. Prior reviews suggest lower breast cancer incidence after MBS, but uncertainty remains across design, menopausal status, procedure type, and confounding control. We conducted a PROSPERO-registered systematic review (CRD420261384078), meta-analysis, and network meta-analysis according to PRISMA. PubMed, Embase/MEDLINE, and Scopus were searched for comparative studies of breast cancer incidence after MBS versus control. Risk of bias was assessed using ROBINS-I and certainty using GRADE. Seventeen studies including 343,531 surgical patients and 1,587,413 controls were included. MBS was associated with lower breast cancer incidence in the primary hazard-ratio analysis (HR 0.75, 95% CI 0.70–0.81; I2 = 0%) and women-only cohorts (HR 0.74, 95% CI 0.67–0.81). Propensity-score-matched analyses showed a larger but heterogeneous association (RR 0.56, 95% CI 0.31–0.99; I2 = 91%). Premenopausal estimates favoured MBS (HR 0.74, 95% CI 0.60–0.91), whereas postmenopausal estimates were not significant (HR 0.73, 95% CI 0.50–1.07). Network estimates favoured sleeve gastrectomy and Roux-en-Y gastric bypass versus control, but no procedure was superior. Certainty ranged very low-to-moderate overall. MBS may be associated with lower breast cancer incidence, but evidence remains observational; future work must clarify causality, patient selection, and procedure effects.