Obese adults without diabetes who received GLP-1 receptor agonists had a 41% lower risk of developing obesity-associated cancers than those who received only dietary and exercise counseling, according to a large real-world analysis led by National Taiwan University Hospital (NTUH).
The findings, published in Annals of Oncology, come from more than 160,000 matched patients drawn from the U.S. TriNetX electronic health-record network between 2014 and 2025. Average follow-up was roughly two years.
The study was led by Dr. Heng-Cheng Hsu (許恒誠) and Dr. Ying-Cheng Chiang (江盈澄) of NTUH's Department of Obstetrics and Gynecology, in collaboration with doctoral candidate Yun-Hao Chang (張雲澔) and Professor Sheng-Hsuan Lin (林聖軒) from the Institute of Statistics at National Yang Ming Chiao Tung University, and researchers from Houston Methodist. The team applied propensity-score matching and inverse probability of treatment weighting to reduce confounding and approximate the conditions of a randomized trial.
Obesity is an established risk factor for 13 cancers. GLP-1 receptor agonists such as semaglutide and tirzepatide are already widely used for weight loss, yet evidence that they might also lower cancer incidence in people without diabetes has been limited. The NTUH-led team set out to test that association.
GLP-1 Protection Consistent Across Sexes, BMI and Drug Type
Patients prescribed the drugs showed a hazard ratio of 0.59 for the combined endpoint of 13 obesity-associated cancers — a 41% lower risk. The reduced risk was observed in both men and women, across BMI categories including those above 40, and with either semaglutide or tirzepatide.
Dr. Jehn-Hsiahn Yang (楊政憲), chair of NTUH's Department of Obstetrics and Gynecology, said the statistical approach converted complex electronic records into high-quality causal evidence before large prospective trials become available. "Before large-scale randomized controlled trials become available, the research team successfully transformed complex electronic health records into a high-quality 'target trial emulation,'" Yang said, adding that the methodology enables real-world data to generate evidence with meaningful causal inference.
Taiwan's Endometrial Cancer Burden Sharpens the Clinical Stakes
The clinical relevance is particularly acute for Taiwan, where endometrial cancer ranks fifth among cancers in women and obesity is a major driver. Dr. Chi-Hau Chen (陳啓豪), chief of the Division of Gynecology, noted that the results suggest GLP-1 agents may offer meaningful preventive potential for this high-risk group.
Dr. Ying-Cheng Chiang, who heads obstetrics and gynecology at NTUH's Hsin-Chu Branch, framed the question plainly: for obese patients without diabetes, can these injections do more than reduce weight? "Our findings demonstrate a significant association," Chiang said, "highlighting the potential of proactive weight management and novel metabolic therapies in cancer prevention."
Lead author Dr. Hsu stressed both the strength and the limits of the data. The study used causal-inference methods to minimize background confounding, but as a retrospective analysis it does not establish cause and effect — prospective trials will be needed to confirm the association. The results do not constitute a new approved indication, Hsu cautioned, and any decision to use the drugs should be made in consultation with a physician.
NTUH said the collaboration with statisticians at National Yang Ming Chiao Tung University and researchers at Houston Methodist underscores the value of real-world data for cancer-prevention research. The team plans further work to clarify the biological pathways involved and to strengthen the evidence base for personalized prevention strategies. （Related： Beating Hep C Is Not Enough: Fatty Liver Keeps Liver Cancer Risk High, NTUH Study Warns ｜ Latest ）
