Weight-loss injections such as Ozempic and Wegovy could significantly reduce cancer risk, according to breakthrough research presented at the American Society of Clinical Oncology (ASCO) annual conference. The GLP-1 receptor agonist drugs, initially developed for diabetes and obesity treatment, were found to reduce the risk of obesity-related cancers by approximately 20% and bowel cancer by up to 50%.
Researchers from Case Western Reserve University (CWRU) analyzed data from more than 34,000 obese patients with a body mass index over 35, comparing cancer rates among those who used weight-loss injections for at least a year against patients who underwent bariatric surgery and those receiving no treatment over a 15-year period.
Cancer Risk Reduction Findings
The study revealed a 19% reduction in cancer risk for both patients using GLP-1 agonists and those who underwent bariatric surgery, despite surgical patients losing "significantly" more weight. This suggests the drugs may have direct cancer-preventive effects beyond weight loss alone.
Dr. Cindy Lin and Dr. Benjamin Liu, co-authors from CWRU, stated: "Our findings are significant in that they could change the paradigm of obesity management by suggesting early intervention with GLP-1 RAs could delay or prevent obesity-related cancer development."
The researchers also observed that patients on weight-loss injections were half as likely to die over the 15-year study period, while bariatric surgery patients showed a 14% reduction in mortality risk.
Potential Mechanisms of Action
Scientists believe multiple mechanisms may explain the cancer-protective effects of GLP-1 drugs. Laboratory and animal studies have demonstrated that these medications can cause cancer cell death and prevent cell multiplication. Additional research suggests they may reduce inflammation, a known contributor to cancer development.
The drugs might also indirectly reduce cancer risk by decreasing patients' desire for alcohol and tobacco, both established carcinogens. This multi-faceted approach could explain why the benefits extend beyond what would be expected from weight loss alone.
Colorectal Cancer Protection
A separate CWRU study examining over 1.2 million patients starting diabetes treatment found that overweight or obese patients using GLP-1 injections were 50% less likely to develop bowel cancer compared to insulin users.
Notably, researchers observed a 44% risk reduction across all diabetes patients using the injections, regardless of weight status. When compared against other common diabetes medications like metformin, SGLT2 inhibitors, sulfonylureas, and thiazolidinediones over a 15-year period, cancer rates were consistently lowest among GLP-1 users.
Professor Rong Xu, director of CWRU's center for artificial intelligence in drug discovery, acknowledged the observational nature of the study but speculated that the mechanisms might involve "both weight loss and additional mechanisms other than weight loss, such as immune modulation, and reduced desire for alcohol drinking or smoking."
Implications for Breast Cancer Treatment
Research presented at the ASCO conference also highlighted potential benefits for breast cancer patients. A study of 75 women with breast cancer from the Memorial Sloan Kettering Cancer Centre found that more than half were taking long-term hormonal therapy drugs that can cause weight gain, subsequently increasing relapse risk.
After 12 months of treatment with GLP-1 injections, these patients lost 5% of their body weight, suggesting the medications could become valuable tools in treating breast cancer and reducing recurrence risk.
Dr. Sherry Shen, the lead author, emphasized: "We know that weight gain is associated with worse survival rates after breast cancer diagnosis. Obesity can also make some cancer therapies less effective. GLP drugs are very promising and we hope someday they will be a tool in cancer treatment."
Co-author Dr. Neil Iyengar added that "reversing weight gain is important from a risk-reduction perspective to reduce the risk of recurrence or cancer spreading."
Broader Therapeutic Potential
The cancer-protective effects add to a growing list of potential benefits for GLP-1 drugs beyond their approved indications. Recent studies have shown these medications can reduce the risk of heart attacks and strokes by approximately 20%.
Researchers are also investigating their potential in treating conditions like alcohol use disorder, dementia, and Alzheimer's disease. Novo Nordisk, the manufacturer of Ozempic and Wegovy, is currently funding three trials to assess the drug's effects in Alzheimer's disease, including its impact on tau protein accumulation in the brain.
Dr. Julie Gralow, chief medical officer of ASCO, expressed optimism about the future of these medications: "I do think that there are so many potential and already proven health benefits to these drugs, that it would be the icing on the cake if we saw that they were also reducing cancers. I am very hopeful about overall improvements in health from this class of drugs."
As research continues, GLP-1 receptor agonists may eventually play a significant role not only in weight management and diabetes care but also in cancer prevention and treatment strategies, potentially transforming multiple areas of healthcare.
