An updated systematic review, meta-analysis, and network meta-analysis of breast cancer incidence after metabolic and bariatric surgery
5 affiliations
- 1Clinical Department of Surgery, University of Edinburgh, Royal Infirmary of Edinburgh
- 2Alexandria University
- 3Academic Unit of Surgery, School of Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow
- 4Medical Research Council (MRC) Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol
- 5Department of Surgery, Endocrine and Metabolic Surgery, Mayo Clinic
Abstract
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.
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BibTeX
@article{mitchell2026updated,
title = {{An updated systematic review, meta-analysis, and network meta-analysis of breast cancer incidence after metabolic and bariatric surgery}},
author = {Sebastian Mitchell and Ryan Gidda and James Lucocq and Georgios Geropoulos and Danielle Clyde and Mohamed H. Zidan and Ross Dolan and Dimitri Pournaras and Mohamed Hany and Omar M. Ghanem and Andrew G. Robertson},
journal = {Scientific Reports},
year = {2026},
month = jul,
doi = {10.1038/s41598-026-64404-z},
url = {https://doi.org/10.1038/s41598-026-64404-z},
note = {CC BY},
}
RIS
TY - JOUR
TI - An updated systematic review, meta-analysis, and network meta-analysis of breast cancer incidence after metabolic and bariatric surgery
AU - Sebastian Mitchell
AU - Ryan Gidda
AU - James Lucocq
AU - Georgios Geropoulos
AU - Danielle Clyde
AU - Mohamed H. Zidan
AU - Ross Dolan
AU - Dimitri Pournaras
AU - Mohamed Hany
AU - Omar M. Ghanem
AU - Andrew G. Robertson
PY - 2026
DA - 2026/07/01
JO - Scientific Reports
DO - 10.1038/s41598-026-64404-z
UR - https://doi.org/10.1038/s41598-026-64404-z
AB - 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.
SN - 2045-2322
ER -