A new study from researchers at Cambridge, Mass.-based Harvard University found that blockbuster GLP-1 drugs such as Ozempic and Zepbound may have a minimal effect on an individual’s risk of developing obesity-related cancers.
The study, published Dec. 9 in Annals of Internal Medicine, is based on a review of 48 randomized controlled trials involving 94,245 participants who had Type 2 diabetes, obesity or were overweight. Of this group, more than 51,000 participants took a GLP-1 drug and 43,000 took a placebo. Participants were observed for a median follow-up period of 16 months.
Researchers found that GLP-1 drugs had “little or no effect” on the risk of developing thyroid, breast, pancreatic or kidney cancer. The study authors said this conclusion was reached with “moderate certainty.”
Findings were similar for eight other obesity-related cancers — colorectal, esophageal, liver, gallbladder, ovarian, endometrial, multiple myeloma or meningioma — though with “low certainty.” GLP-1s effect on the risk of gastric cancer is “very uncertain,” according to the study.
The study’s lead author, Cho-Han Chiang, MD, an internal medicine resident at Mount Auburn Hospital in Cambridge — a Harvard teaching hospital — told NBC News on Dec. 8 the study has two major limitations: none of the trials included in the review were designed to measure cancer outcomes and there was a relatively short follow-up period.
Dr. Chiang and outside experts told NBC News that longer-term studies are needed to better understand whether GLP-1s reduce the risk of cancer.
“I am relieved with the findings of this study that there does not appear to be any increased cancer signals,” Susan Wolver, MD, director of the weight loss program at Richmond, Va.-based VCU Health, told the news outlet. “But I am also not dismayed that there was no reduction in the development of cancer or metastases, because I think we just didn’t have a long enough time.”
Several earlier studies have shown GLP-1s may diminish the risk of certain cancers. A breakdown of the findings can be found here.
