Could GLP-1 weight-loss drugs boost survival for colon cancer patients?

Colon cancer patients taking GLP-1 medications were less than half as likely to die within five years compared to those who weren’t on the drugs. – Image credit UC San Diego Today

CANCER DIGEST – Nov. 15, 2025 – An analysis of data from nearly 7,000 colon cancer patients treated at cancer centers throughout California showed that patients who were taking a class of drug called glucagon-like peptide-1 (GLP-1) were more likely to survive compared to similar patients who were not taking the drug. The study appeared in the Nov. 11, 2025 issue of Cancer Investigation.

The study, led by Raphael Cuomo, PhD., of the Department of Anesthesiology at the University of California San Diego,  analyzed the medical records of 6,800 colon cancer patients treated at medical centers associated with the University of California system across the state. 

After taking into consideration age, body mass index (BMI), disease stage and other health factors, the researchers found that the use of GLP-1 drugs reduced the risk of dying of colon cancer.  Of those taking the drug, 15.5 percent died within 5 years of diagnosis compared to 37.1 percent of those not taking the drug.

GLP-1 drugs are a class of drugs first developed to regulate blood sugar in type-II diabetes patients, but has since been shown to be effective for weight loss. These drugs include Ozempic®, Wegovy®, and Mounjaro® to name a few. 

While the study does not address the biological effects of the drug that might explain the cancer survival benefit, the researchers did find that the benefit was most pronounced in people with very high BMI (over 35), suggesting that GLP-1 drugs may help counteract the inflammatory and metabolic conditions that worsen colon cancer. 

In laboratory studies, these drugs have been shown to reduce systemic inflammation, improve insulin sensitivity and promote weight loss, all factors that can contribute to slowing cancer tumor growth. Other studies have suggested that GLP-1 drugs may in fact directly prevent cancer cell growth, and promote cancer cell death. 

The study investigators, however, emphasized that their study cannot say what the mechanism of survival benefit in these patients is. Additional research, including clinical trials are needed to definitively determine whether the survival benefit seen in this analysis represents a direct anti-cancer effect or an indirect result of improved metabolism.

Sources: University of California San Diego press release, and Cancer Investigation.