CHICAGO — Research led by Cleveland Clinic found that glucagon-like peptide-1 (GLP-1) weight-loss drugs may reduce progression to stage 4 in several obesity-related cancers. The study, which has not yet been peer-reviewed, will be presented at the 2026 ASCO Annual Meeting in Chicago.

The retrospective study included 12,112 patients diagnosed with stage 1 to stage 3 obesity-related cancers. Half of the participants began taking a GLP-1 medication—such as semaglutide, tirzepatide, dulaglutide, liraglutide, lixisenatide, or pramlintide—after their cancer diagnosis. The other half started a DPP-4 inhibitor, known as “gliptins,” which belong to a different class of diabetes medications.

Compared to patients taking gliptins, those using GLP-1 drugs showed lower rates of progression to stage 4 disease: a 50% risk reduction for non-small cell lung cancer, 43% for breast cancer, 31% for colorectal cancer, and 38% for liver cancer. Prostate, pancreatic, and kidney cancers also showed lower rates of spread among GLP-1 users, but those differences were not statistically significant.

“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 Mark David Orland, MD, of the Taussig Cancer Institute at Cleveland Clinic. “It provides early evidence that future studies are worth pursuing.” he added.

The research also found that tumors with higher levels of GLP-1 receptors were linked to better survival outcomes. Patients whose tumors expressed more GLP-1 receptors were about one-third less likely to die during the study period. The incidence of adverse side effects was similar between the two medication groups.

The study was observational and retrospective, not a randomized clinical trial, and therefore cannot prove that GLP-1 drugs directly prevent cancer progression. Researchers noted that other factors—including participants’ overall health, weight loss, and metabolic improvements—may have influenced the results. For some cancer types, the study may not have included enough patients to detect statistically significant differences.

The findings suggest that GLP-1 pathways may directly influence how certain cancers grow or spread. However, the researchers emphasized that further randomized clinical trials are needed to evaluate these preliminary results and determine the specific mechanisms by which GLP-1 drugs might control cancer progression.