GLP-1 Drugs: No Cancer Link, Reduced Obesity-Related Cancers
A large study found GLP-1 drugs don't raise cancer risk; instead, they cut obesity-related cancers by 7% and overall mortality by 8%.
A close-up of a microscope lens capturing a vibrant blue cancer cell, symbolizing the groundbreaking findings: © catalin - stock.adobe.com
A study presented during the 2025 American Society of Clinical Oncology Annual Meeting press briefing on Wednesday, May 21, 2025, found, in an analysis of more than 170,000 patients, that GLP-1 drugs were not associated with higher cancer rates, and actually led to a decrease in obesity-related cancers and deaths.
There was a 7% decrease in obesity-related cancer among patients who used GLP-1 receptor agonists (HR, 0.93; 95% CI, 0.88-0.98; P = .005) with 2501 events vs 2671 events in patients who were DPP-4 users. For females, events observed were 1754 for GLP-1 and 1898 for DPP-4 (HR, 0.92; 95% CI, 0.86-0.98; P = .01). For males, there were 747 events with GLP-1 and 773 with DPP-4 (HR, 0.95; 95% CI, 0.86-1.05; P = .29).
There was an 8% decrease in all-cause mortality (HR, 0.92; 95% CI, 0.87-0.97; P = .001) with 2783 events with GLP-1 vs 2961 for DPP-4. For females, there were 1219 events with GLP-1 and 1514 events with DPP-4 (HR, 0.80; 95% CI, 0.74-0.86; P <.001). For males, events were 1564 with GLP-1 and 1447 with DPP-4 (HR, 1.04; 95% CI, 0.96-1.11; P = .34).
Investigators assessed 14 types of cancer and found that the protective association between GLP-1 and cancer incidence was driven by those of the colon (HR, 0.84; 95% CI, 0.72-0.98; P = .02) and the rectum (HR, 0.72; 95% CI, 0.56-0.93; P = .01). Of note, there was no evidence of adverse association with pancreatic cancer.
Medullary thyroid cancer could not specifically be assessed in this study due to the small sample size and is included in the warning labels for multiple GLP-1 medications, however, there was a lack of association between GLP-1 use and thyroid cancer as a whole in this assessment.
“Findings extend the value of GLP-1 medicines beyond blood sugar control, weight, heart, and kidney health to potential cancer prevention in adults who are high-risk,” Lucas A. Mavromatis, research assistant in the Division of Precision Medicine in the Department of Medicine at NYU Grossman School of Medicine, said during the presentation. “The effect size is small, follow-up was short, and assessed medications are primarily weaker, ‘diabetes dose’ formulations; long-term studies are needed to confirm the durability of effect and safety.”
Data were collected between 2013 and 2023 from 43 health system networks and included electronic health records and insurance claims. Those included in the analysis were adults with type 2 diabetes and had a body mass index of 30 kg/m2 or more, and were started with either a GLP-1 medicine or a DPP-4 inhibitor for the first time.
Comparison groups included 85,015 pairs, and each GLP-1 starter was paired with 1 DPP-4 starter of similar age, sex, race, weight, laboratory values, year of prescription, and medical history. This followed the target trial emulation framework.
Outcomes included the first diagnosis of any 14 obesity-related cancers or death from any cause. Follow-up was from the first prescription until cancer, death, or the last recorded visit, with an average coverage of 3.9 years.
The background for the study was the gap in knowledge of the long-term impact of GLP-1 medications on the risk of cancer.
“GLP-1 treatments remain a strong option for people with diabetes and obesity and may favorably affect cancer risk. Decisions should balance benefits, costs, and [adverse] effects in discussion with clinicians,” Mavromatis concluded.
