Researchers at the Cleveland Clinic have found that GLP-1 receptor agonists reduce the risk of tumours progressing to stage IV in four cancers: non-small cell lung cancer, breast cancer, colorectal cancer and hepatocellular carcinoma. In addition, overall survival significantly improved for seven types of malignancies. The findings, based on real-world clinical data, were presented at the ASCO 2026 congress.
For their analysis, the researchers used the global TriNetX medical network, which contains 145 million patient records. The final sample included about 10,000 people with type 2 diabetes and stage I–III cancer who started taking GLP-1 agonists after their cancer diagnosis. Their outcomes were compared with a group of the same size who received DPP-4 inhibitors – a different class of glucose-lowering drugs – instead of GLP-1 agonists.
The results were striking. In non-small cell lung cancer, progression to stage IV was seen in 10% of patients taking GLP‑1 agonists, compared with 22.3% in the control group. For breast cancer, the figures were 10.2% versus 20.1%; for colorectal cancer, 13.4% versus 22.2%. A trend toward a protective effect was also observed in pancreatic cancer, but the difference did not reach statistical significance.
Overall survival on GLP‑1 agonists increased for seven cancer types. The strongest effect was seen in breast cancer, where survival improved by 45%. The frequency of side effects in the GLP‑1 agonist group did not differ significantly from the control group. Lead author Marc Orland called the results grounds for cautious optimism. “For a patient battling both diabetes and cancer, the very idea that their glucose-lowering drug might also be working in their favour against cancer is very encouraging,” he said.
Meanwhile, Orland stressed that randomized controlled trials are needed, as well as a better understanding of the precise biological mechanisms. Key questions remain: is the protective effect linked to immunomodulation, direct action on GLP‑1 receptors in tumour or stromal cells, reduction of systemic inflammation, or metabolic reprogramming? The authors plan to investigate these issues further.
Another study published earlier found that taking heartburn drugs (proton pump inhibitors) together with GLP‑1 drugs increases the risk of gastrointestinal problems. In addition, such patients more often require endoscopy.