GLP-1 receptor agonists demonstrated a 35% reduction in breast cancer incidence among 111,646 women aged 45-80 with BMI ≥25 undergoing routine breast imaging. The protective effect persisted after propensity matching for confounding variables including age, race, BMI, and diabetes status (OR 0.695, 95% CI 0.590-0.819). This finding extends beyond GLP-1's established metabolic benefits, suggesting direct anti-cancer mechanisms that warrant investigation. The magnitude of protection rivals that seen with established preventive interventions like tamoxifen, potentially opening new therapeutic avenues for high-risk women. However, the retrospective design limits causal inference—women prescribed GLP-1 agonists may have unmeasured health behaviors or genetic factors influencing cancer risk. The 2022-2025 timeframe also means limited long-term follow-up data. While obesity is an established breast cancer risk factor, this degree of protection suggests GLP-1 receptors may influence tumor biology beyond weight loss alone, possibly through direct effects on cell proliferation or insulin signaling pathways. Prospective randomized trials are essential to confirm causality and establish optimal dosing strategies for cancer prevention.