PURPOSE: Excess weight is a key modifiable risk factor for breast cancer. Glucagon-like peptide-1 receptor agonists (GLP-1) promote weight loss and improve metabolic health, but their effect on breast cancer risk remains unclear.
METHODS: We conducted a retrospective cohort study from January 1, 2022, to June 30, 2025, using electronic health records. We identified 217,025 unique patients who underwent breast imaging, restricting to women aged 45 to 80 years with a BMI ≥ 25 and a documented imaging outcome (n = 111,646; median age 61). The primary outcome was breast cancer detection. GLP-1 use was defined as a first prescription prior to the exam date and assessed in relation to race, ethnicity, age, and type 2 diabetes. To address potential confounding between these covariates and GLP-1 exposure, we performed one-to-one, case-control matching using propensity scores based on age, race, ethnicity, highest BMI, breast density, and history of type 2 diabetes. The propensity matching to the GLP-1 use group was performed using the greedy nearest neighbor approach.
RESULTS: GLP-1 exposure was associated with a lower incidence of breast cancer (OR 0.649, 95% CI 0.569-0.741; p < 0.0001). In the matched logistic regression (30,528 observations; 600 cancer cases), GLP-1 exposure was associated with a lower breast cancer incidence (OR 0.695, 95% CI 0.590-0.819; p < 0.0001).
CONCLUSION: In this large observational study of women undergoing breast imaging at a major academic center and affiliated sites, GLP-1 treatment was associated with a lower incidence of breast cancer, independent of age, race, ethnicity, BMI, breast density, and diabetes. Findings support the need for prospective trials investigating GLP-1 agonists for breast cancer prevention.
GLP-1 Therapies