Could GLP-1 drugs help prevent breast cancer? New study points to a possible link

By Pooja Toshniwal PahariaReviewed by Susha Cheriyedath, M.Sc.Jun 3 2026

A major breast imaging study links GLP-1 agonists to lower breast cancer incidence, raising hopes for a new prevention strategy while underscoring the need for prospective clinical trials.

Study: GLP-1 Agonists Are Associated With a Significant Reduction in Breast Cancer Incidence in Women. Image Credit: Love Employee / Shutterstock

In a recent study published in JCO Oncology Practice, researchers explored the impact of glucagon-like peptide-1 receptor agonist (GLP-1 RA) use on breast cancer incidence. Among more than 100,000 overweight and obese women, they found that GLP-1 agonist use was associated with lower breast cancer incidence.

The findings were consistent after accounting for age, race, ethnicity, body mass index (BMI), breast density, and diabetes. Women using GLP-1 agonists showed lower odds of developing breast cancer compared with those who did not use these drugs. In fact, in this study, less than two percent of women with GLP-1 exposure were diagnosed with breast cancer.

Based on these findings, GLP-1 agonists, which are commonly used for weight management and diabetes, may be associated with lower breast cancer incidence among women. If confirmed in larger prospective trials, these widely used drugs could offer a new potential approach to breast cancer prevention, especially for women with excess body weight.

Obesity is an important modifiable risk factor for breast cancer. In other words, sustained weight loss may help reduce breast cancer risk in some populations. Scientists have found that GLP-1 agonists can help reduce body weight and enhance metabolic regulation. They are also increasingly finding that these drugs may help reduce inflammation, a hallmark of cancer. Whether GLP-1 agonists can also reduce breast cancer risk, however, remains unclear. This is because previous studies focused on women with higher BMI since they are most likely to be prescribed GLP-1 agonists.

Researchers also combined results from different clinical trials with different selection criteria, and only a few participants actually developed cancer. This makes it difficult to draw conclusions. GLP-1 users also visit doctors more frequently, which is why they may undergo cancer screening more often, leading to higher detection rates. Bariatric surgery helps reduce breast cancer risk through sustained weight loss, but may not be practical at a population level.

Study Design

In the present study, researchers evaluated the association between GLP-1 agonist use and breast cancer incidence. They analyzed electronic medical records of the University of Pennsylvania Health System between January 2022 and June 2025.

These records included more than 217,000 women who underwent breast imaging. For the present analysis, the team selected a subset of 111,646 overweight and obese women (BMI ≥25, median age 61 years) aged 45-80 years. Breast imaging results were available for these individuals.

The researchers determined breast cancer incidence as the primary study outcome. They defined GLP-1 agonist use as a documented prescription for GLP-1 before the breast imaging examination. Logistic regression models estimated odds ratios (ORs) for analysis.

To make a fair comparison, the team used one-to-one propensity-score matching to pair participants based on several clinical and demographic factors. These included age, race, ethnicity, breast density, highest BMI, and diabetes. They used the greedy nearest-neighbor method to construct propensity-score-matched groups.

GLP-1 Use and Lower Incidence

The study included 111,646 overweight and obese women. In this sample population, 15,264 individuals (14%) used GLP-1 agonists, whereas 96,382 individuals (86%) did not use these medications. Among women taking GLP-1 agonists, less than two percent (n=247) received a breast cancer diagnosis.

In the unmatched analysis, GLP-1 agonist use was linked to lower breast cancer incidence (OR, 0.65). After matching, the analysis included 30,528 observations and 600 breast cancer cases. Researchers found similar results.

After matching for clinical and demographic factors, women using GLP-1 medications continued to show lower odds of developing breast cancer (OR, 0.70). Women using GLP-1 medications showed lower odds of receiving a breast cancer diagnosis compared with those who did not use these drugs (OR, 0.7).

In absolute terms, breast cancer risk in the matched analysis was 1.62% among GLP-1-exposed women and 2.31% among matched women without exposure, corresponding to an absolute risk reduction of 0.69% during the study period.

Early studies suggest that GLP-1 agonists, such as exenatide and liraglutide, may reduce breast cancer cell proliferation and viability by altering cellular energy metabolism. In mouse models, scientists found that drugs such as tirzepatide, which act on both glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptors, could reduce tumor growth.

Similar benefits were seen with calorie restriction, suggesting that weight loss may have been a major contributing factor for these effects. Genetic studies suggest that changes affecting GIP signaling may increase breast cancer risk, indicating that GLP-1 and GIP pathways could influence cancer development.

However, the researchers emphasized that the study was observational and hypothesis-generating. The analysis could not determine whether GLP-1 agonists directly reduced cancer incidence, nor could it assess medication adherence, dose, treatment duration, cumulative exposure, or the effects of different drug formulations. Some women classified as unexposed may also have received GLP-1 medications outside the health system.

Breast Cancer Prevention 

The findings demonstrate that GLP-1 users had nearly 30% lower odds of being diagnosed with breast cancer. These effects were similar in magnitude to risk reductions observed with tamoxifen in early studies, although this comparison reflects effect size rather than equivalent evidence strength or clinical readiness.

Although researchers did not directly compare both drugs, the findings could be especially relevant for women who have difficulty tolerating existing medications such as tamoxifen. If larger-scale prospective trials confirm the findings, GLP-1 agonists could potentially be explored as adjuncts to existing breast cancer prevention strategies. This may expand the options available to patients for breast cancer prevention, particularly for women for whom current preventive medications are unsuitable.

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