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

Weight loss treatments, including medication and surgical procedures, may help lower the risk of obesity-associated cancers (OAC) in people with obesity and type 2 diabetes, a study shows. Semaglutide and bariatric surgery were associated with lower cancer rates in individuals with overweight/obesity and T2D, with non-significant lower rates also observed with tirzepatide.

The University of Leicester study, carried out by researchers funded by National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre (BRC), 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 drugs semaglutide and tirzepatide, bariatric surgery and with people given medication to treat their diabetes.

Dr Jonathan Goldney (Credit: University of Leicester)

“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,” said the University of Leicester’s Dr Jonathan Goldney, co-lead author of the study. “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.”

In 64,178 matched pairs (mean follow-up 911 days), semaglutide (vs. DPP-4i) was associated with lower rates of composite OAC (HR: 0.88; 95% CI: 0.82–0.95), colorectal (0.80; 0.67–0.97), liver (0.75; 0.60–0.95) and pancreatic (0.76; 0.60–0.96) cancers. In 19,682 matched pairs (mean follow-up 435 days), tirzepatide (vs. DPP-4i) was associated with a non-significant lower rate of composite OAC (0.84; 0.69–1.01) but a significant lower rate of ovarian cancer (0.31; 0.10–0.95).

In 9,642 matched pairs (mean follow-up 1746 days), bariatric surgery (vs. DPP-4i) was associated with lower rates of composite OAC (0.85; 0.74–0.98), liver (0.56; 0.32–0.97) and uterine cancers (0.59; 0.38–0.90), and higher rates of gastric cardia cancer (10.54; 1.35–82.38) and oesophageal cancer (4.78; 1.04–21.87).

“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,” said Melanie Davies, Director of the NIHR Leicester BRC and Professor of Diabetes Medicine at the University of Leicester, who co-led the study. “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 findings were reported in the paper, 'Diabetes remission and diabetic complications of bariatric surgery vs. medical management in patients with type 2 diabetes: A meta-analysis of randomized controlled trials', published in Diabetes Obesity and Metabolism. To access this paper, please click here