GLP-1 Drugs Show Remarkable Reduction in Death Rates Among Colon Cancer Patients

A new study from the University of California San Diego has uncovered a striking association between GLP-1 receptor agonists—the class of medications behind Ozempic, Wegovy, and Mounjaro—and dramatically lower death rates in people diagnosed with colon cancer. This finding has sparked widespread curiosity, not only because these drugs are already famous for their effects on blood sugar and weight loss, but also because the study suggests they may influence cancer outcomes in a surprisingly powerful way.

The research analyzed data from more than 6,800 colon cancer patients across all University of California Health locations. Out of this large group, those who were taking GLP-1 medications showed a 15.5% five-year mortality rate, while those not using these drugs had a significantly higher rate of 37.1%. In simple terms, patients on GLP-1 drugs were less than half as likely to die within five years.

To make sure the results weren’t skewed by other factors, the researchers adjusted the data for age, BMI, disease severity, and general health conditions. Even after all these adjustments, the apparent survival benefit remained strong, pointing toward what seems to be an independent and robust protective effect.

One of the most interesting patterns in the data is that the survival boost appeared to be strongest in patients with a BMI over 35—a category classified as severe obesity. This aligns with what scientists already know about obesity: high body fat contributes to inflammation, poor metabolic health, and hormonal imbalances, all of which can worsen cancer progression. Since GLP-1 drugs can improve many of these metabolic issues, it makes sense that their benefits might be most obvious in patients whose weight is already placing stress on their body.

Researchers also explored possible biological explanations for this effect. GLP-1 receptor agonists are known to:

• Lower systemic inflammation
• Improve insulin sensitivity
• Promote substantial weight loss
• Reduce metabolic strain

All these changes can make the body less supportive of tumor growth. Beyond that, laboratory studies have shown that GLP-1 drugs may play a more direct role in cancer biology. Some experiments suggest they might help block cancer cell growth, encourage cancer cell death, and even reshape the tumor microenvironment—the surrounding biological landscape that influences how tumors grow and spread.

However, the researchers stress that these findings, while exciting, are still observational. That means the study can show a connection, but it cannot prove that GLP-1 drugs cause better survival outcomes. For example, some patients on GLP-1 drugs may have had healthier behaviors or better access to medical care, which could also influence survival. The authors are clear that we still need controlled clinical trials to understand what’s really happening.

The study, led by Raphael Cuomo, Ph.D., appears in Cancer Investigation and marks an important moment in a growing wave of interest in how metabolic medications may influence cancer outcomes. With obesity rates rising and GLP-1 drugs becoming increasingly common, the idea that these medications might offer benefits beyond weight loss—and possibly affect cancer progression—opens up a major new area of research.

Understanding GLP-1 Drugs Beyond Diabetes and Weight Loss

The growing popularity of medications like Ozempic, Wegovy, and Mounjaro has brought GLP-1 receptor agonists into the spotlight. These medications were originally developed for type 2 diabetes, but their powerful effects on appetite, insulin regulation, and metabolic health have transformed them into widespread tools for weight management.

But GLP-1 is involved in more than metabolism. The hormone influences gut function, inflammation, insulin signaling, and even aspects of the immune system. Because of this, researchers have increasingly wondered if these medications might play a role in slowing certain diseases, including those influenced by metabolic dysfunction—like cancer.

Why Metabolic Health Matters in Cancer

Cancer isn’t just a genetic or environmental disease. It’s also heavily influenced by metabolic conditions inside the body. Patients with obesity often have:

• Higher levels of inflammation
• Elevated insulin and insulin-like growth factors
• Higher blood sugar
• More fat around organs, including visceral fat
• Increased oxidative stress

All these factors can create an environment that supports tumor development and progression. Because GLP-1 drugs target many of these metabolic pathways, it’s not surprising that researchers are now investigating whether these medications might play an unexpected role in cancer survival.

What Makes the New Study Different

Several earlier studies have explored whether GLP-1 drugs reduce the risk of developing colorectal cancer. Some found protective associations; others found no clear link.

What makes this new UC San Diego study stand out is that it focuses on people who already have colon cancer and examines whether these medications influence survival rather than prevention.

Key features of this study include:

• A large group of 6,871 patients
• Inclusion of all University of California Health centers
• Five years of follow-up survival data
• Statistical controls for multiple health factors
• Comparison between GLP-1 users and non-users

Even after accounting for confounding factors, GLP-1 users had dramatically lower mortality, suggesting the association is not easily explained away.

What This Does Not Mean (Important Clarifications)

Because this study is observational, it cannot prove:

• That GLP-1 drugs directly treat colon cancer
• That patients should start GLP-1 medications for cancer survival
• That GLP-1 drugs replace standard cancer treatments

Even the research team emphasized that more scientific work is needed. The next steps should include clinical trials, ideally with thousands of patients, to determine whether GLP-1 drugs directly influence cancer biology or whether the benefits simply come from improved metabolic health.

The Road Ahead for GLP-1 and Cancer Research

The findings highlight an urgent need for:

• Randomized clinical trials
• Detailed tracking of cancer stage, tumor markers, and treatment regimens
• Mechanistic studies exploring how GLP-1 drugs affect tumors at the molecular level
• Research on other obesity-related cancers, such as pancreatic, breast, and liver cancers

With millions of people now using GLP-1 medications worldwide, understanding their broader effects is becoming increasingly important.

Research Source

The Influence of GLP-1 Receptor Agonists on Five-Year Mortality in Colon Cancer Patients (2025)
https://doi.org/10.1080/07357907.2025.2585512