New research indicates that GLP-1 medications like Ozempic and Wegovy may lower breast cancer risk by 30%, urging further investigation into their potential as preventive tools.
Recent research has unveiled an intriguing correlation between GLP-1 medications, such as Ozempic and Wegovy, and a potential decrease in breast cancer risk. An extensive study encompassing over 110,000 women reveals that those on these diabetes and weight-loss drugs exhibited a reduced likelihood of developing breast cancer.
The findings, presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting and published in JCO Oncology Practice, discovered that women taking GLP-1 medications were about 30% less likely to be diagnosed with breast cancer compared to their counterparts not using these drugs. Elizabeth McDonald, MD, PhD, from the University of Pennsylvania’s Perelman School of Medicine, emphasized that while this observational study does not establish a definitive cause-and-effect relationship, it underscores the necessity of exploring these medications in the context of cancer prevention.
Understanding GLP-1 Medications
GLP-1 medications mimic the hormone glucagon-like peptide-1, playing a critical role in regulating appetite and blood sugar levels. Originally developed for treating type 2 diabetes, these medications have surged in popularity as weight-loss options across the U.S. Their rise in use has prompted interest in their broader implications, including possible connections to cancer risk reduction.
Despite the promising observational data linking GLP-1 drugs to lowered cancer risk, researchers stress that larger, methodologically rigorous clinical trials are essential to confirm these findings and establish the mechanisms at play. McDonald's team, for instance, is gearing up to launch a multisite clinical trial specifically aimed at examining whether GLP-1 medications can lower breast cancer rates among women deemed high risk.
Study Details and Findings
The comprehensive study analyzed electronic health records from 111,646 women aged 45 to 80, all part of the Penn Medicine health system, who had a body mass index (BMI) of 25 or higher and had undergone breast imaging between January 2022 and June 2025. Out of these participants, 15,264 had prescriptions for GLP-1 medications, while 96,382 did not.
To assess breast cancer diagnosis rates, two separate analyses were conducted. The first considered the entire cohort, while the second matched 30,528 GLP-1 users with nonusers based on critical demographic factors. Both analyses revealed consistent results: an approximately 35.1% reduction in breast cancer odds for the overall cohort, and a 30.5% reduction within the matched analysis.
Despite these promising results, the research comes with caveats. It did not differentiate between specific GLP-1 drugs or account for variables such as treatment duration, genetic predispositions, or cancer characteristics. Future studies will aim to address these gaps.
Possible Mechanisms Behind the Effects
Maintaining a healthy weight is widely recognized as a key factor in breast cancer prevention, particularly post-menopause, where excess weight becomes a significant risk factor. Given that GLP-1 medications are effective for weight management, some of the correlation between these drugs and lower breast cancer rates likely stems from weight loss.
However, researchers believe there could be additional biological mechanisms at work. Chronic inflammation, for instance, has been implicated in breast cancer development, and GLP-1 medications may mitigate this through various pathways. Additionally, these drugs have the potential to influence metabolic processes and epigenetic factors that govern gene expression, further contributing to a possible cancer-preventive effect.
Future Directions for Cancer Prevention
Current preventive measures for breast cancer are somewhat limited, primarily encompassing regular screenings and, for select high-risk patients, prophylactic surgeries. While drugs like tamoxifen can significantly decrease breast cancer incidence in high-risk women, concerns about side effects often deter many from use.
In contrast, GLP-1 medications are already prevalent in the user population, positioning them as a promising avenue for further research in cancer prevention. McDonald notes a desire to pursue better options to curb breast cancer risk, motivated by improvements seen in breast cancer survival rates in recent decades.
Looking ahead, the findings of this study point to the potential of GLP-1 medications extending beyond weight management, warranting further exploration in the context of breast cancer prevention and treatment.
This research was supported by the American College of Radiology Center for Research and Innovation, the Pennsylvania Breast Cancer Coalition, and the Abramson Cancer Center.
Materials provided by University of Pennsylvania School of Medicine. Note: Content may be edited for style and length.
Discussion
Sign in to join the discussion.