Weight loss treatments for people with diabetes and obesity could lower the risk of obesity-related cancers

Weight loss treatments, including medication and surgical procedures, may help lower the risk of obesity-related cancers in people with obesity and type 2 diabetes, a new study shows.

The University of Leicester study, carried out by researchers funded by National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre (BRC) and published in Diabetes, Obesity and Metabolism in September 2025 investigated data from around 180,000 people.  

Researchers looked at the incidence of a number of cancers including breast, colorectal, gallbladder, liver, ovarian, pancreatic and uterine cancers in adults with obesity and type 2 diabetes. They compared the incidence of cancer in those who received the weight loss drug semaglutide, those who received tirzepatide those who had undergone bariatric surgery, and also with people given medication to treat their diabetes. 

The University of Leicester’s Dr Jonathan Goldney, co-lead author of the study, said: “We observed a lower incidence of cancer in people who had undergone weight-loss surgery. Around 15% fewer cancers were observed in these people.

“There were also strong indicators that people prescribed semaglutide had lower incidence too, with around 12% few cancers observed in these people. 

“Our study findings make sense, as there is a growing amount of research suggesting that obesity causes cancer. Through sustained weight reduction, these therapies may also help reduce the risk of developing cancer.”

Testimony Ipaye from the Department of Genetics, Genomics and Cancer Sciences at the University of Leicester, also a lead author, added:  “Because this study included data from tens of thousands of people, our findings give us confidence that the potential benefits of weight loss treatments for cancer prevention could be relevant to a wide range of patients in the real world. 

“The potential impact on future healthcare and patient outcomes is hugely encouraging.”

Melanie Davies, Director of the NIHR Leicester BRC and Professor of Diabetes Medicine at the University of Leicester, who co-led the study said: “We are working hard to understand the emerging effects of weight loss drugs as they become more widely prescribed for obesity and type 2 diabetes. 

“These findings are exciting as they give us hope that the benefits may also extend into cancer prevention and reduction, which could inform treatment management and prevention in the future.”

The NIHR Leicester BRC is part of the NIHR and hosted by the University Hospitals of Leicester NHS Trust in partnership with the University of Leicester, Loughborough University and University Hospitals of Northamptonshire NHS Group.