A study found that the glucagon-like peptide-1 (GLP-1) weight-loss drug Semaglutide, by Danish pharmaceutical company Novo Nordisk, has effects on preventing obesity-related cancers in addition to weight loss. Compared to obesity surgery, which involves stomach resection, the cancer prevention effect was significantly higher, raising expectations for preventing various cancers caused by obesity.
Dr. Yael Wolff Sagy and her research team at Clalit Health Services, Israel's largest health care organization, noted on the 11th in Malaga, Spain, at the 2025 European Congress on Obesity that "administering GLP-1 receptor agonists was confirmed to have a 41% higher effect on preventing obesity-related cancers than individuals who underwent obesity surgery."
Cancers related to obesity include 13 types such as colorectal cancer, liver cancer, pancreatic cancer, and breast cancer. The results of this study were published in the international academic journal Lancet's sister journal, eClinical Medicine.
GLP-1 weight-loss drugs help suppress appetite, slow down digestion, and maintain a feeling of fullness for longer. Initially developed as a treatment for type 2 diabetes, their weight-loss effects led to an expansion of the target diseases to include obesity. Recent reports have indicated their effectiveness in various diseases such as Alzheimer's disease, osteoarthritis, and sleep apnea, with related research ongoing.
First-generation GLP-1 weight-loss drugs include Saxenda and 'Byetta' (exenatide) from British company AstraZeneca, while second-generation drugs consist of Wegovy (semaglutide) from Novo Nordisk and 'Mounjaro' or 'Zepbound' (tirzepatide) from Eli Lilly.
The research team compared the cancer risk in 6,350 adults with a body mass index (BMI) of 35 or higher and no cancer history who had undergone obesity surgery or received GLP-1 weight-loss drugs over 7.5 years. Typical obesity surgeries reduce the size of the stomach or alter the length of the small intestine to absorb nutrients.
The analysis revealed that patients who underwent obesity surgery experienced twice the weight-loss effect compared to those receiving GLP-1 weight-loss drugs; however, the cancer prevention effect was found to be 41% higher with GLP-1. The research team stated that while obesity surgery also reduces cancer risk by 30-42%, given the various problems associated with surgery, GLP-1 is more effective in preventing obesity-related cancers.
Dror Dicker, a professor at Tel Aviv University in Israel who led the study, said, "The cancer prevention effect of GLP-1 class drugs is likely due to multiple mechanisms, including reduced inflammation," adding, "Next-generation weight-loss drugs will likely be effective in preventing obesity-related cancers and weight loss."
Experts expressed hope that the results of this study will herald a completely new era in preventive oncology.
Mark Lawler, a professor at Queen's University Belfast in the UK, mentioned, "Obesity surgeries reduce the risk of obesity-related cancers by about a third, and this data shows that GLP-1 can reduce that risk by half," saying, "Targeting GLP-1 may be a groundbreaking approach to prevent difficult-to-treat cancers such as colorectal, pancreatic, and breast cancer, as inflammation decreases."
Jason Halford, a former president of the European Association for the Study of Obesity and a professor at the University of Reading in the UK, said, "GLP-1 receptor agonists may not only prevent cancer but also have potential therapeutic effects," and added, "We need to verify whether administering GLP-1 class weight-loss drugs to newly diagnosed cancer patients can enhance their survival prospects."
However, concerns were raised about the potential side effects of GLP-1 class weight-loss drugs in cancer treatment. The research team at Tel Aviv University also stated, "Further studies are needed to determine whether GLP-1 class weight-loss drugs increase the risk of cancers unrelated to obesity."
References
eClinical Medicine (2025), DOI: https://doi.org/10.1016/j.eclinm.2025.103213