Perioperative GLP‐1 Receptor Agonist Use and 30‐Day Outcomes After Breast Cancer Surgery: A Retrospective Cohort Study

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly prescribed for diabetes and obesity, but their perioperative safety in breast cancer surgery remains uncertain. This study evaluated the association between perioperative GLP-1 RA use and 30-day postoperative outcomes after breast cancer surgery. MATERIALS AND METHODS: This retrospective cohort study included adults undergoing breast cancer surgery at a tertiary center (January 2024-August 2025). Exposure was active GLP-1 RA use within 30 days preoperatively, verified via pharmacy records. The primary outcome was a composite 30-day surgical morbidity endpoint (surgical site infection [SSI], flap necrosis ≥ grade II, seroma requiring aspiration, or implant/expander loss). Secondary outcomes included venous thromboembolism (VTE), readmission, reoperation, and length of stay. Multivariable regression and inverse probability of treatment weighting (IPTW) addressed confounding. RESULTS: The analytic cohort comprised 750 patients (209 exposed, 541 unexposed; median age 51 years). Exposed patients had higher body mass index and diabetes prevalence. After adjustment, GLP-1 RA exposure was not associated with SSI (adjusted odds ratio [AOR] 1.28, 95% CI 0.81-2.03), seroma (AOR 1.22, 95% CI 0.83-1.79), or flap necrosis ≥ grade II (AOR 1.41, 95% CI 0.83-2.40). No secondary outcome showed independent association with exposure. Prolonged length of stay (≥ 3 days) occurred in 26.8% of patients overall and was attributable primarily to drain management requirements, extent of surgery, and metabolic comorbidity rather than GLP-1 RA exposure. CONCLUSION: Perioperative GLP-1 RA use was not independently associated with increased short-term complications after breast cancer surgery. Multicenter studies are needed to confirm safety across settings.