A new study from the University of California San Diego suggests that glucagon-like peptide-1 (GLP-1) receptor agonists, a class of medications originally developed for type 2 diabetes, may have benefits that extend far beyond blood sugar and weight management. These drugs, which include semaglutide (sold as Ozempic and Wegovy) and tirzepatide (known as Mounjaro), are already well known for helping people lose weight and manage metabolic conditions. Now, researchers have discovered that they might also be linked to better survival outcomes in colon cancer patients.
The study analyzed medical records from more than 6,800 people diagnosed with colon cancer across University of California Health facilities. Patients who were taking GLP-1 medications were less than half as likely to die within five years compared to those not using the drugs (15.5% versus 37.1%). This striking difference points to a potentially powerful new use for drugs that are already transforming diabetes and obesity treatment.
The research was led by Raphael Cuomo, Ph.D., an associate professor in the Department of Anesthesiology at UC San Diego School of Medicine and a member of the UC San Diego Moores Cancer Center. His team used the University of California Health Data Warehouse to review outcomes across the state’s academic medical centers.
After accounting for important factors such as age, body mass index (BMI), cancer severity, and other health conditions, the team found that people taking GLP-1 drugs still had a significantly lower risk of death. This consistency suggests the protective benefit of GLP-1 therapy may be independent of other medical or lifestyle variables.
Why GLP-1 Drugs Might Protect Against Cancer
The benefit appeared strongest in patients with obesity (BMI over 35). This finding hints that GLP-1 drugs may help offset some of the inflammation and metabolic stress that can make cancer harder to treat.
Scientists are exploring several possible explanations for this effect. GLP-1 receptor agonists are known to lower inflammation throughout the body, enhance insulin sensitivity, and promote weight loss — all factors that can influence cancer growth and progression. Experimental studies in laboratories also indicate that GLP-1 drugs may directly inhibit the growth of tumor cells, encourage cancer cell death, and alter the surrounding environment within tumors to make them less supportive of disease spread.
However, researchers caution that it is still unclear whether the lower death rate seen in this study reflects a direct anti-cancer action or an indirect result of improved overall metabolic health.
Next Steps: Clinical Trials Needed
Dr. Cuomo emphasized that the findings are observational, meaning they do not yet prove that GLP-1 drugs directly improve cancer outcomes. These results highlight an urgent need for clinical trials to test whether GLP-1 medications can actually enhance cancer survival, particularly among patients with obesity-related cancers.
The study was published in Cancer Investigation on November 11, 2025.
