A new review of nearly 100,000 participants suggests that glucagon-like peptide-1 receptor agonists (GLP-1RAs), popular medications for type 2 diabetes and obesity, are unlikely to increase the risk of most obesity-related cancers. The findings provide reassurance amid growing global use of drugs such as semaglutide and tirzepatide.
The research, published this week, analyzed data from 48 randomized placebo-controlled trials drawn from major scientific databases, including PubMed, Embase, and the Cochrane Central Register of Controlled Trials. The included studies compared GLP-1RAs with placebo and tracked cancer outcomes across multiple sites, including thyroid, pancreatic, colorectal, breast, kidney, and several reproductive and gastrointestinal cancers.
Cancer Risk Appears Minimal
Overall, GLP-1RAs showed little or no effect on the likelihood of developing the most commonly monitored obesity-related cancers. For example, compared with placebo, the odds ratio for thyroid cancer was 1.37 (95% CI 0.82 to 2.31), while pancreatic cancer had an odds ratio of 0.84 (CI 0.53 to 1.35). Similar results were seen for breast and kidney cancers, all with moderate certainty of evidence.
For colorectal, oesophageal, liver, gallbladder, ovarian, or endometrial cancers, as well as multiple myeloma and meningioma, the certainty of evidence was lower but indicated minimal difference between GLP-1RA and placebo groups. Data on gastric cancer remained too limited for clear conclusions. Sensitivity analyses confirmed that results were consistent across different durations of follow-up, drug types, and dosage levels.
Longer-Term Data Still Needed
Although the analysis suggests no major safety concerns, researchers cautioned that existing trials were not designed to detect cancer outcomes and typically followed participants for short periods. Because many cancers develop over years, long-term studies are still needed to fully understand potential risks or protective effects associated with GLP-1 drugs.
For now, the evidence indicates that GLP-1RAs do not appear to meaningfully alter cancer risk, supporting their continued use for diabetes control and weight management under medical supervision.
Reference
Ko A et al. Risk for cancer with glucagon-like peptide-1 receptor agonists and dual agonists: a systematic review and meta-analysis. Annals of Internal Medicine. 2025; https://doi.org/10.7326/ANNALS-25-0223.
