New research suggests GLP-1 medicines may be linked to a lower risk of several obesity-related cancers, but scientists caution the findings do not prove the drugs directly prevent cancer.
Use of GLP-1 drugs including Ozempic and Wegovy has surged in recent years. Although these medications were initially developed to help manage type 2 diabetes, they are now being used far more widely for weight loss and obesity treatment.
Researchers say the shift has been significant, with recent survey data suggesting that about one in eight U.S. adults has taken a GLP-1 drug at some point, and many current users now take them primarily for obesity management rather than diabetes.
Aparna Kamat, MD, director of the Division of Gynecologic Oncology at Houston Methodist Hospital, explained that earlier research largely centered on diabetic patients.
“Most previous studies examining GLP-1 medications and cancer risk were conducted in patients with type 2 diabetes.”
The latest study instead looks specifically at people taking the drugs who do not have diabetes, a group researchers say has been underrepresented despite now making up a major share of users.
“This is the population that has been invisible in the literature, and it is now the largest group using these drugs. They are younger, they don’t have diabetes, and they are experiencing some of the sharpest increases in obesity-associated cancers we’ve seen in decades.”
According to the research, GLP-1 use was associated with a lower overall risk of obesity-related cancers in people with obesity but without diabetes. In the study, the strongest signals appeared in certain cancers, including endometrial cancer, where the reduction was especially pronounced.
Kamat cautioned that the results do not prove the drugs directly prevent cancer.
“We are not ready to say these drugs prevent cancer – our study cannot prove causation,” Kamat noted.
“But we are ready to say this finding demands a serious answer. Given the rapidly increasing use of these medications, even a modest reduction in cancer incidence could have important public health implications.”
The study, published in Annals of Oncology, analyzed records from more than 229,000 obese adults without diabetes and matched GLP-1 users with people who received diet and exercise counseling. Over an average follow-up of about two years, GLP-1 use was associated with a 41 percent lower overall incidence of obesity-related cancers. The largest reduction reported in the study was for endometrial cancer, which fell by 58 percent.
The study looked at 13 obesity-associated cancers, including endometrial, breast, colorectal, kidney, pancreatic, thyroid, ovarian, esophageal, gastric, liver and gallbladder cancers, as well as multiple myeloma and meningioma. Researchers say the findings are especially notable because obesity is a known risk factor for many of these cancers, and rising obesity rates have been linked to increasing cancer burden in younger adults.
Kamat also suggested the medications may be doing more than simply helping people lose weight, saying they could be affecting cancer biology as well and might ‘not just shrinking the patient’, but also the ‘tumor itself’.
Even so, scientists have long understood that obesity itself raises the risk for many cancers, meaning more work is needed to determine how much of the apparent benefit comes from weight loss alone and how much may stem from other effects of the drugs.
David Greenberg, MD, FACP, section chief of Hematology/Oncology at Hackensack Meridian Jersey Shore University Medical Center in New Jersey, was not involved in the study but said the findings were not unexpected.
“We know these drugs not only diminish appetite and aid weight loss, but they also likely affect cardiovascular health, improve insulin sensitivity, and thus decrease overall inflammation in the body.
“Anything that decreases inflammation likely also decreases a person’s overall cancer risk. So I believe other factors are at play besides losing weight.”
Experts say the results are encouraging, but they are still considered early and observational. Larger, longer-term studies will be needed before anyone can say whether GLP-1 drugs truly help prevent cancer, or whether the lower risk seen so far reflects a mix of weight loss, better metabolic health and other biological effects.