Popular glucagon-like peptide-1 (GLP-1) weight-loss drugs may help slow the spread of some cancers, according to new research to be presented at a major medical conference.
Research led by Cleveland Clinic found that the medications may reduce the spread of several obesity-related cancers, including lung, breast, colorectal and liver cancers.
The findings will be presented at the 2026 ASCO Annual Meeting next week in Chicago.
According to a press release, the real-world retrospective study included 12,112 patients with the following types of obesity-related cancers, ranging from stage 1 to stage 3.
- Breast adenocarcinoma
- Prostate adenocarcinoma
- Non-small cell lung cancer (NSCLC)
- Colorectal adenocarcinoma
- Hepatocellular carcinoma (liver cancer)
- Renal cell carcinoma
- Pancreatic adenocarcinoma
Half of the participants started a GLP-1 medication – semaglutide, tirzepatide, dulaglutide, liraglutide, lixisenatide or pramlintide – after their cancer diagnosis.
The other half began taking a DPP-4 inhibitor comparator “gliptins,” a different class of diabetes medications, the study noted.
Compared to the patients taking gliptins, the GLP-1 users were found to have significantly lower progression to stage 4 disease for four types of cancers.
The biggest risk reduction was for non-small cell lung cancer (50%), followed by breast cancer (43%), colorectal cancer (31%) and liver cancer (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 lead study author Mark David Orland, MD, of the Taussig Cancer Institute at Cleveland Clinic, in the release.
“It provides early evidence that future studies are worth pursuing.”
Three other types of cancer – prostate, pancreatic and kidney – also had lower rates of spread among those taking GLP-1s, but those differences were “not statistically significant,” the researchers noted.
Tumors with higher levels of GLP-1 receptors — proteins that help cells respond to GLP-1 hormones and drugs — were also linked to better survival outcomes, according to the study findings.
Overall, patients whose tumors had more of these receptors were about one-third less likely to die during the study period.
The incidence of adverse side effects was similar between GLP-1 and gliptin groups.
The findings suggest that GLP-1 pathways may directly influence how some cancers grow or spread, though researchers say more studies are needed to understand the mechanism behind this effect.
The study, which has not yet been peer-reviewed, had some limitations, according to the researchers. As it was retrospective and observational in design – as opposed to a randomized clinical trial – it couldn’t prove that GLP-1 drugs directly prevent cancer progression.
Other factors, such as participants’ health conditions, weight loss and metabolic improvements, may have influenced the results, researchers noted.
For some specific cancer types, there may not have been enough patients represented to detect statistically significant differences.
Further randomized clinical trials are needed to evaluate these preliminary findings and to determine the specific ways in which GLP-1s control cancer progression.
