Obesity is a well-known risk factor for breast cancer development and recurrence, and glucagon-like peptide 1 (GLP-1) receptor agonists have emerged as effective treatments for weight management. At the 2025 San Antonio Breast Cancer Symposium, researchers presented a study examining real-world GLP-1 use among breast cancer patients and its potential links to clinical outcomes, social determinants of health (SDOH), and circulating tumor DNA (ctDNA) results.
The study analyzed electronic health records from 708,406 patients diagnosed with breast cancer between January 2011 and February 2025. Using AI-assisted data extraction, investigators evaluated documented GLP-1 use, associated clinical and sociodemographic factors, and correlations with ctDNA testing and positivity.
Who is Using GLP-1?
Overall, 7.6% of patients had documented GLP-1 use, primarily for diabetes, weight loss, cardiovascular issues, or obstructive sleep apnoea. GLP-1 therapy was more common among patients with a body mass index of 30 or higher, non-Latinx Black patients, telemedicine users, and those living in rural areas. Use was lower among older patients (over 75), those with advanced-stage disease (stage IV), patients with HR-/HER2- tumors, Latinx and Asian patients, individuals with limited English proficiency, and those receiving care at community medical centers rather than academic institutions.
Links to Tumor Activity
Notably, GLP-1 use was associated with higher rates of ctDNA testing (2.8% vs. 1.5%) and lower ctDNA positivity (25.8% vs. 31.6%). This suggests a potential connection between GLP-1 therapy and reduced circulating tumor activity, raising questions about whether these medications may play a supportive role in oncology care beyond weight management.
Implications and Next Steps
The study underscores how clinical factors, sociodemographic, and SDOH influence GLP-1 use and highlights disparities in access. Researchers emphasized the need for further studies to determine whether GLP-1 medications directly impact breast cancer outcomes and to ensure equitable access to supportive therapies across diverse patient populations.
This analysis represents one of the largest real-world investigations of GLP-1 use in breast cancer, offering new insights into its potential benefits and avenues for future research.
Reference
Ryals CA et al. Real-world glucagon-like peptide 1 use and association with clinical characteristics, social determinants, and circulating tumor DNA positivity in patients with breast cancer. Abstract PD8-07-02. SABCS 2025; 9-12 December.
