GLP-1 Receptor Agonists Linked to Improved Survival Outcomes in Breast Cancer

New research published in JAMA Network Open suggests glucagon-like peptide-1 receptor agonists (GLP-1 RAs), widely used for obesity and type 2 diabetes (T2D) management, may also be associated with improved survival and reduced recurrence risk among patients with breast cancer. The retrospective cohort study, led by investigators at Virginia Commonwealth University Massey Comprehensive Cancer Center, analyzed electronic health records from more than 840,000 patients diagnosed with breast cancer between 2006 and 2023 and found a significant association between GLP-1 RA use and improved long-term outcomes.^1,2

The findings add to a growing body of evidence suggesting GLP-1 therapies may have broader oncologic implications beyond weight loss and glycemic control.^1-4

Expanding Interest in GLP-1 Therapies

GLP-1 receptor agonists, including semaglutide (Ozempic, Wegovy; Novo Nordisk) and tirzepatide (Zepbound, Mounjaro; Eli Lilly), were initially developed for the treatment of patients with T2D before later gaining FDA approvals for chronic weight management.² Their rapid rise in popularity has transformed obesity treatment, with approximately 12% of Americans reportedly having used GLP-1 medications for weight loss, according to a RAND Corporation report.⁵

Researchers have increasingly investigated whether the metabolic and anti-inflammatory effects of GLP-1 RAs could influence cancer development and progression. Obesity and T2D are both associated with worse breast cancer outcomes, including increased recurrence risk and mortality.⁶ Prior studies have also linked weight reduction following breast cancer diagnosis with improved cardiovascular health and survival outcomes.¹

“This study suggests that GLP-1 drugs may offer protective benefits, potentially improving survival and recurrence risk in some female patients with breast cancer—whether this is related to weight control, improved cardiovascular health, or other mechanisms remains to be studied,” senior author Bernard F. Fuemmeler, PhD, MPH, associate director for population sciences and the Gordon D. Ginder, MD, Chair in Cancer Research at VCU Massey Comprehensive Cancer Center, said in a news release.¹

Reduced Mortality and Recurrence Risk

Investigators evaluated breast cancer survivors who were prescribed GLP-1s for obesity or T2D management. According to the findings, GLP-1 use was associated with a lower risk of all-cause mortality over a 10-year follow-up period compared with patients who did not receive these therapies.^1,2

Additionally, breast cancer survivors using GLP-1 RAs experienced a significantly lower risk of cancer recurrence over the same timeframe. Researchers noted the results align with emerging preclinical evidence examining the relationship between GLP-1 signaling, inflammation, metabolic regulation, and tumor biology.¹

“Our findings align with emerging preclinical research and contribute to a growing body of literature related to GLP-1 RA use in oncology settings,” lead author Kristina L. Tatum, PsyD, MS, of the VCU School of Public Health, said in the release.¹

The findings also build upon prior research, which found GLP-1 use was associated with an overall reduced risk of 12 out of 13 obesity-related cancers among adults with obesity.³ In that retrospective cohort study published in JAMA Oncology, investigators observed reduced risks across multiple malignancies, including breast, colorectal, ovarian, thyroid, pancreatic, liver, and lung cancers.^3,7

Researchers in that study reported a 14% lower risk of breast cancer among GLP-1 users compared with nonusers. The authors noted the consistent trend toward reduced cancer incidence across several hormone-sensitive malignancies may warrant additional investigation into the potential protective effects of GLP-1 therapies.^3,7

Additional SABCS Findings Highlight Potential Benefits

Additional data presented at the 2025 San Antonio Breast Cancer Symposium (SABCS) further highlighted the growing interest in GLP-1 therapies within oncology. Researchers reported that patients with hormone receptor-positive breast cancer taking hormonal therapy experienced meaningful weight loss when using GLP-1 medications, with participants losing an average of 12.7% of their body weight after 6 months and 17.4% after 12 months.⁴

Another analysis presented at the conference found patients with breast cancer and obesity taking both hormonal therapy and GLP-1s had a 46% lower risk of death from any cause during a median follow-up of approximately 5.5 years compared with matched patients who were not receiving GLP-1 therapies.⁴

Still, investigators cautioned that more research is needed to fully understand the benefits and risks of these therapies in oncology populations. “We are just starting to shed light on this,” said Jasmine Sukumar, MD, a medical breast oncologist at MD Anderson Cancer Center and session moderator at SABCS.³

Implications for Oncology Care

The new findings may have important implications for survivorship care, particularly among patients with obesity or metabolic disease. However, investigators emphasized that the observational nature of the study prevents researchers from establishing causation, and randomized clinical trials will be needed to determine whether GLP-1 RAs directly improve cancer outcomes.¹

“Our study underscores the potential of GLP-1 RAs as an adjunct strategy for improving cancer-related outcomes among patients with breast cancer, although clinical trials are needed to inform effective therapeutic approaches and clinical decision making,” Fuemmeler said.¹

REFERENCES

1. Virginia Commonwealth University. Popular weight loss, diabetes drugs linked to improved breast cancer survival. EurekAlert! News Release. Published May 11, 2026. Accessed May 12, 2026. https://www.eurekalert.org/news-releases/1127691

2. Tatum KL, Dahman B, Stevenson A, et al. Survival and Recurrence With GLP-1 Receptor Agonists in Breast Cancer. JAMA Netw Open. 2026;9(5):e2612133. Published 2026 May 1. doi:10.1001/jamanetworkopen.2026.12133

3. Gerlach A. Study Finds GLP-1 Receptor Agonists May Reduce Cancer Risk in Adults with Obesity. Pharmacy Times. Published August 25, 2026. Accessed May 12, 2026. https://www.pharmacytimes.com/view/study-finds-glp-1-receptor-agonists-may-reduce-cancer-risk-in-adults-with-obesity

4. Santora T. 5 New Findings About GLP-1s and Breast Cancer. Breastcancer.org. Published March 12, 2026. Accessed May 12, 2026. https://www.breastcancer.org/news/GLP-1s-research-SABCS

5. Nearly 12 Percent of Americans Have Used GLP-1 Weight Loss Drugs; Medications Are Most Used by Women Aged 50 to 64. RAND News Release. Published August 6, 2025. Accessed May 12, 2026. https://www.rand.org/news/press/2025/08/nearly-12-percent-of-americans-have-used-glp-1-weight.html

6. Key Statistics for Breast Cancer. American Cancer Society. Published January 13, 2026. Accessed May 12, 2026. https://www.cancer.org/cancer/types/breast-cancer/about/how-common-is-breast-cancer.html

7. Dai H, Li Y, Lee YA, et al. GLP-1 Receptor Agonists and Cancer Risk in Adults With Obesity. JAMA Oncol. 2025;11(10):1186-1193. doi:10.1001/jamaoncol.2025.2681