Do GLP-1 Weight-Loss Medications Lower Colon Cancer Risk? New Study Offers Encouraging Clues

A New Look at Diabetes Drugs and Cancer Prevention

GLP-1 medications—like semaglutide (Ozempic/Wegovy) and liraglutide—are widely used to treat type 2 diabetes and support weight loss. But scientists have also wondered whether these drugs might help lower the risk of certain cancers linked to obesity, especially colorectal cancer (CRC).

A study published in JAMA Oncology explored this question by analyzing health records from more than one million people with type 2 diabetes who had never used diabetes drugs before. The findings suggest that GLP-1 medications may be linked to a lower risk of colorectal cancer compared with several other diabetes treatments. While more research is needed, these early results offer exciting possibilities for long-term cancer prevention.

Why Colorectal Cancer Risk Matters in Type 2 Diabetes

Colorectal cancer is one of the most common cancers worldwide. According to the study, people with type 2 diabetes, especially those who also have overweight or obesity, face higher-than-average risk of developing this cancer.

GLP-1 drugs help people with diabetes by lowering blood sugar and often helping with weight loss—both of which may influence cancer risk. Because obesity is a major risk factor for developing colorectal cancer, researchers wondered whether GLP-1 medications might also have a protective effect on the colon.

Previous research has shown that some other diabetes medications, such as insulin or sulfonylureas, may increase or decrease cancer risk. This study aimed to compare GLP-1 medications directly with seven other common diabetes drugs to see whether people taking GLP-1 drugs were less likely to develop colon cancer over time.

What Did the Research Discover?

This was a nationwide, retrospective cohort study, meaning researchers looked back at anonymized medical records rather than running a new trial. They used the TriNetX electronic health record platform, which contains information from more than 101 million patients, including 7.4 million people with type 2 diabetes

Study Approach

Using records from 2005 to 2019, researchers identified 1,221,218 adults with type 2 diabetes who had never taken diabetes medications before and never had colorectal cancer. They compared people who were prescribed GLP-1 drugs with people prescribed one of seven other medication types, including:

• insulin
  
• metformin
  
• DPP-4 inhibitors
  
• SGLT2 inhibitors
  
• sulfonylureas
  
• thiazolidinediones (TZDs)
  
• alpha-glucosidase inhibitors
  

To make sure the groups were as similar as possible, researchers matched patients by:

• age, sex, race/ethnicity
  
• lifestyle factors such as exercise, diet, alcohol, smoking
  
• family history of cancer
  
• obesity status and other medical problems
  
• colonoscopy history
  

Main Results

Over a 15-year follow-up period, people taking GLP-1 medications had a significantly lower risk of developing colorectal cancer than people taking several other diabetes drugs.

Key findings include:

• Compared with insulin: 44% lower risk (HR 0.56)
  
• Compared with metformin: 25% lower risk (HR 0.75)
  
• Lower risk also seen when compared with SGLT2 inhibitors, sulfonylureas, and TZDs
  
• The reduction was even stronger in people with overweight or obesity, including:
  
  • 50% lower risk vs insulin
    
  • 42% lower risk vs metformin
    
  • 23–37% lower risk vs several other drugs
    

The reduced risk appeared in both men and women.
Not every comparison reached statistical significance, but the overall pattern suggested a meaningful protective effect.

What This Means

The study suggests that GLP-1 medications may help lower colorectal cancer risk, possibly due to weight loss, reduced inflammation, improved blood sugar control, or other biological effects. But because this research used observational data, it cannot prove cause and effect.

How Can I Apply This Information?

It’s important to remember that this is research, not medical advice or a treatment guideline. GLP-1 drugs are not approved for preventing cancer. However, the findings offer helpful insights:

• People already using GLP-1 medications for diabetes or weight loss may receive an added long-term benefit, beyond blood sugar control.
  
• This study cannot prove that GLP-1 medications directly prevent cancer. More randomized controlled trials are needed before any formal recommendations can be made.
  

If you have type 2 diabetes, talk with your healthcare provider about the most appropriate and safe medication options for your overall health.

Source:

Wang L, Wang W, Kaelber DC, Xu R, Berger NA. GLP-1 receptor agonists and colorectal cancer risk in drug-naive patients with type 2 diabetes, with and without overweight/obesity. JAMA Oncol. 2024;10(2):256-258. doi:10.1001/jamaoncol.2023.5573. Accessed by: https://jamanetwork.com/journals/jamaoncology/fullarticle/2812769