GLP-1 Drugs May Slow Cancer Spread

Recent research indicates that glucagon-like peptide-1 (GLP-1) weight-loss medications may hinder the progression of certain cancers linked to obesity. This study, conducted by the Cleveland Clinic, will be presented at the 2026 ASCO Annual Meeting in Chicago.

These drugs appear to reduce the spread of lung, breast, colorectal, and liver cancers. The findings stem from a retrospective study involving 12,112 patients with various obesity-related cancers, including stage 1 to stage 3 cancers.

The types of cancers examined include:

• Breast adenocarcinoma
• Prostate adenocarcinoma
• Non-small cell lung cancer (NSCLC)
• Colorectal adenocarcinoma
• Hepatocellular carcinoma (liver cancer)
• Renal cell carcinoma
• Pancreatic adenocarcinoma

About half of the study participants began taking a GLP-1 medication, such as semaglutide, tirzepatide, dulaglutide, liraglutide, lixisenatide, or pramlintide, after their cancer diagnosis. The other half used a different class of diabetes medications called DPP-4 inhibitors or “gliptins.”

Compared to patients using gliptins, those on GLP-1 medications saw a notable reduction in progression to stage 4 cancer. The most significant reduction was observed in non-small cell lung cancer at 50%, followed by breast cancer at 43%, colorectal cancer at 31%, and liver cancer at 38%.

Our study found that use of GLP-1 drugs, compared to DPP-4 inhibitors and other antidiabetic drugs, was associated with a meaningful reduction in cancer progression across four solid tumor types, said Dr. Mark David Orland, lead researcher at the Taussig Cancer Institute, Cleveland Clinic.

While other cancers, such as prostate, pancreatic, and kidney, also showed reduced spread among GLP-1 users, these findings were not statistically significant.

Tumors with elevated levels of GLP-1 receptors—proteins that mediate cell responses to GLP-1—were associated with better survival rates. Patients with more GLP-1 receptors in their tumors were roughly one-third less likely to die during the study.

Both GLP-1 and gliptin groups experienced similar adverse side effects. The study suggests that GLP-1 pathways might directly alter cancer growth, though more research is needed to fully understand this effect.

Despite its promising results, the study faced limitations. It was observational rather than a randomized clinical trial, limiting its capacity to definitively prove the relationship between GLP-1 drugs and cancer progression. Factors such as patient health conditions, weight loss, and metabolic changes might have influenced outcomes.

Further randomized clinical trials are necessary to validate these preliminary findings and clarify how GLP-1 medications might impede cancer progression.