Abstract PS5-11-16: Impact of GLP-1 Receptor Agonist Exposure on the Long-Term Survival in Breast Cancer Patients

Abstract Background: Obesity is a known risk factor for the development of breast cancer, and weight gain after treatment of early-stage disease is associated with worse outcomes, including cancer-specific outcomes. Some of the proposed mechanisms for adverse outcomes in obese patients include the pro-tumorigenic environment from circulating cytokines, impaired adipokine function, and differential efficacy of systemic treatments. Weight reduction strategies in breast cancer patients have largely been unsuccessful. The GLP-1 receptor agonists (GLP-1RAs) have the potential to produce meaningful weight loss; however, the impact of these agents on breast cancer outcomes has not been well characterized. Methods: Diabetic patients with invasive breast cancer diagnosed between 2009 and 2024 were identified using the City of Hope tumor registry through an IRB approved protocol. Patients were divided into those who had been treated with GLP-1RA after breast cancer diagnosis (cases, n = 232) versus those who had not (controls, n = 722). The groups were compared using t-tests for continuous variables and chi-square tests for categorical variables. Multivariable logistic regression models were used to examine differences between cases and controls, while multivariable Cox proportional hazards models were used to examine differences in overall mortality. Included in the multivariable models were the following covariates: diagnosis year, age group (