GLP-1 Receptor Agonists in Breast Cancer: A New Frontier in Obesity and Prognosis Management

Obesity is a well-established risk factor for both the incidence and poorer clinical outcomes of Breast Cancer (BC), particularly among hormone receptor-positive postmenopausal women. However, conventional weight loss interventions have yielded limited success in altering cancer prognosis. Recently, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), such as semaglutide and tirzepatide, have emerged as effective pharmacologic agents for sustained weight loss and are under investigation in oncology. This narrative review synthesizes evidence linking obesity to poor BC prognosis and evaluates the therapeutic potential of GLP-1 RAs in this context. Mechanistically, obesity exacerbates tumor progression through hormonal imbalance, chronic inflammation, and adipokine and insulin signaling, targets that may be modifiable through weight reduction. GLP-1 RAs offer multiple benefits, such as appetite suppression, delayed gastric emptying, and enhanced insulin sensitivity. Clinical studies in BC patients have shown weight loss ranging from 2.3% to 5%, likely attenuated by concurrent endocrine therapy. Preliminary data suggest that GLP-1 RA use does not increase the risk of cancer recurrence and may reduce cardiovascular morbidity. However, prospective studies are needed to confirm long-term oncologic safety and efficacy. Disparities in access and cost remain barriers to widespread adoption. Nevertheless, GLP-1 RAs represent a promising adjunct to manage obesity among BC patients, potentially improving metabolic health and long-term cancer outcomes.