A drug commonly used to treat type 2 diabetes could also effectively protect against colorectal cancer (CRC), based on a new analysis by researchers in the US.
The drug in question is a class of medications known as glucagon-like peptide-1 receptor agonists – more easily referred to as GLP-1 RAs. These medications, which include the widely-known 'wonder drug' sold under the commercial name Wegovy, have also previously been linked to weight loss and reducing the risk of cardiovascular problems.
We know that being overweight or having type 2 diabetes increases CRC risk, and that these medications help in those areas – but they also reduced CRC cases in people who weren't overweight or obese.
"Our results clearly demonstrate that GLP-1 RAs are significantly more effective than popular anti-diabetic drugs, such as Metformin or insulin, at preventing the development of CRC," says Nathan Berger, medical research scientist at the Case Western Reserve University School of Medicine.
Berger and his colleagues drilled down into data collected on more than 1 million patients in a national US health record database, identifying patients with type 2 diabetes who had taken differing treatments for the condition. Matches were then made based on as many characteristics as possible, including sex, race, age, and socio-economic status.
In 22,572 patients with type 2 diabetes who had been treated with insulin, 167 cases of CRC were recorded. In a matched pool of 22,572 type 2 diabetes patients treated with GLP-1 RAs, there were just 94 cases of CRC – a 44 percent reduction.
The team also looked at two groups of 18,518 matched type 2 diabetes patients treated with the drug metformin, as opposed to GLP-1 RAs. Here the CRC case numbers were 153 vs 96 respectively – that's a 37 percent reduction, though the hazard ratio (adding in factors such as how long each patient was monitored for) drops this down to 25 percent.
When the groups were limited to patients with obesity or who were overweight, the comparative risk reduced further. In these cohorts, GLP-1 RAs were associated with 50 percent reduction in CRC cases compared to insulin, and 58 percent reduction in those treated with GLP-1 RAs versus those treated with metformin.
These results aren't enough to prove the GLP-1 RAs in particular were protecting against CRC – even though the different groups were matched up as well as possible – but they definitely suggest that more research and clinical trials are worth pursuing.
Those trials would be able to look at GLP-1 RAs more closely, to try and analyze how they might be stopping CRC from developing.
With obesity continuing to be more common, and CRC the second-leading cause of cancer mortality in the US – responsible for some 52,550 deaths per year – any improvements in treatment will certainly be welcome.
"To our knowledge, this is the first indication this popular weight-loss and anti-diabetic class of drugs reduces incidence of CRC, relative to other anti-diabetic agents," says Rong Xu, a biomedical informatician at the Case Western Reserve University School of Medicine.
The research has been published in JAMA Oncology.