- GLP-1s, a class of diabetes and weight-loss drugs that includes Ozempic and Mounjaro, could be associated with reduced colorectal cancer risk, but more research is needed.
- Researchers looked at the records of more than 1.2 million diabetes patients and compared GLP-1s to other commmon antidiabetic medications like metformin and insulin.
- In addition to diabetes and weight loss, studies of GLP-1s have shown other potential benefits including reduced cardiovascular disease risk.
A research letter published today in
Researchers at Case Western Reserve University, combed over 15 years and 100 million patient records to look at how different diabetes medications affected cancer outcomes.
Building off of the known association between colorectal cancer and obesity (it is one of
“This study is really driven by a well-established hypothesis,” said Dr. Rong Xu, PhD, a Professor of Biomedical Informatics, and Director of the Center for AI in Drug Discovery at the Case Western Reserve University School of Medicine, and the study’s co lead researcher.
Xu has developed algorithms that allow her team to probe huge databases, looking at over 100 million patients, and develop incisive questions about the trends they observe.
Dr. Nathan Berger, a Professor of Experimental Medicine and Director of the Center for Science Health and Society at the Case Western Reserve University School of Medicine, and the study’s other co-lead researcher told Healthline:
“What we’ve done is we’ve been able to condense 15 years into a couple of weeks or months of investigation to give a clear signal that this really needs to be studied on a much larger basis because of its importance.”
Large retrospective research like this is excellent for finding correlations but doesn’t prove causations. That is, it doesn’t prove that taking GLP-1s reduces cancer risk, but its findings are enticing enough to warrant further investigation.
“There are limitations to this dataset. For example, how long were patients taking GLP-1 (which the study does not provide.). In this type of dataset, granular information on duration of treatment is not known and differences found could relate to underlying differences between patients who were prescribed or not prescribed GLP-1 medications,” said Dr. Sun Kim, an Associate Professor of Endocrinology at Stanford University. Kim wasn’t affiliated with the research.
Berger and Xu used patient records from over 100 million individuals to create a final study population of just over 1.2 million diabetes patients who had been prescribed antidiabetic medications between 2005-2019.
To be included in the population study, patients had to have been diagnosed with type-2 diabetes and then treated with an antidiabetic drug, such as metformin, insulin, or a GLP-1. Researchers then compared those drugs’ effects by matching individuals with as many similar characteristics as possible, things like age, ethnicity, lifestyle factors (exercise, diet, drinking, and smoking), medical conditions, and socio-economic status.
For patients treated with insulin (22,572 patients), there were 167 cases of colorectal cancer over the observation period. In an equal-sized group of similar individuals who were prescribed a GLP-1 there were only 94 cases, a 44% reduction in the occurrence of colorectal cancer.
There were similar results for patients who took the popular diabetes drug metformin. In a group of 18,518 patients there were 153 cases of colorectal cancer, compared with only 96 in a similar group that took GLP-1s — that’s a 25% reduction.
Interestingly, the research suggests even greater risk reduction in patients who were not overweight or obese.
“[GLP-1s] are controlling obesity and they’re controlling diabetes, which have multiple mechanisms by which they lead to an increase in cancer. But it’s more than that,” said Berger. “We divided up patients between those that have obesity and overweight, and those that don’t, and we saw an even greater effect of these drugs in patients who did not have overweight and obesity.”
At this point, however, they don’t wish to speculate on what those additional mechanisms could be.
“It’s very difficult to speculate on mechanisms since we can’t establish causation based on this data analysis. Globally, though, I’m intrigued by another potential benefit of this drug class, especially since the news in the colorectal cancer world of late has been alarm due to the increased incidence in younger patients,” said Dr. Ursina Teitelbaum, an Associate Professor of Hematology-Oncology at the University of Pennsylvania and Section Chief of Gastrointestinal Oncology at Penn Medicine’s Abramson Cancer Center. Teitelbaum wasn’t affiliated with the research.
GLP-1s have been around since 2005, initially prescribed to treat diabetes. However, they’ve exploded in popularity only recently, largely owing to the reputation of injectable forms of semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) as transformative weight-loss drugs.
“I know it seems incredulous that one drug could be associated with so many benefits. However, we should remember that obesity is associated with many health issues including cancer,” said Kim.
“I think we are seeing so many benefits with GLP-1 drugs because this is the first time we have had a medication that can significantly lead to clinically meaningful weight loss [greater than 10% of body weight],” she added.
However, those benefits don’t come without some serious side effects for some individuals. GLP-1s work by mimicking a hormone that slows digestion and increases feelings of fullness and satiety. The drugs work in the gut and have been associated with a multitude of gastrointestinal issues, especially nausea and vomiting. More serious side effects, including blocked intestines, which is potentially fatal, are also possible.
Mounjaro, Wegovy, and Ozempic all carry a box warning about this serious side effect.
The cost of the drugs, which can be thousands of dollars per month, is also prohibitively expensive for many people if their insurance does not cover the medication.
As for whether GLP-1s will one day include reducing colorectal cancer risk among its myriad benefits, that remains to be seen.
“We can’t say what’s going on yet for this drug class with regard to cancer risk, but it is an interesting field to explore, and this article is taking the first stab at looking at it. It’s too soon to tell,” said Teitelbaum.
GLP-1s, drugs like Ozempic and Mounjaro, could reduce the risk of colorectal cancer, according to new research in JAMA Oncology.
The large, retrospective study looked at the records of more than 1.2 million diabetes patients.
Despite the findings, clinical trials would be needed to conclude if there is a causal relationship between the drugs and reduced cancer risk.