Antidiabetic Drug May Reduce Colorectal Cancer Incidence

CLEVELAND, OH — A groundbreaking study by researchers at Case Western Reserve University (CWRU) suggests a class of medications used to treat type 2 diabetes may also reduce the risk of colorectal cancer (CRC).

The findings, published recently in JAMA Oncology, support the need for clinical trials to determine whether these medications could prevent one of the deadliest types of cancers. Eventually, the medications may also show promise in warding off other types of cancer associated with obesity and diabetes.

“Our results clearly demonstrate that GLP-1 RAs are significantly more effective than popular antidiabetic drugs, such as Metformin or insulin, at preventing the development of CRC,” said Nathan Berger, MD, the Hanna-Payne professor of experimental medicine at the Case Western Reserve School of Medicine and the study’s co-lead researcher.

What are GLP-1 RAs?

Glucagon-like peptide-1 receptor agonists, or GLP-1 RAs, are medications to treat type 2 diabetes. Usually given by injection, they can lower blood sugar levels, improve insulin sensitivity, and help manage weight. They’ve also been shown to reduce the rates of major cardiovascular ailments. The protective effect of GLP-1 RAs is noted in patients with or without overweight/obesity.

“To our knowledge,” said co-lead researcher Rong Xu, PhD, a professor at the School of Medicine, “this is the first indication that this popular weight-loss and antidiabetic class of drugs reduces incidence of CRC, relative to other antidiabetic agents.”

The population-based study

Since GLP-1 RAs are effective antidiabetic and weight-loss agents, the researchers hypothesized they might reduce the incidence of CRC. Using a national database of over  100 million electronic health records, the researchers conducted a population-based study of more than 1.2 million patients. These individuals had been treated with antidiabetic agents from 2005–19; the CWRU team examined the effects of GLP-1 RAs on their incidence of CRC, compared to those prescribed other antidiabetic drugs.

Population-based research means matching as many people as possible with the same characteristics—sex, race, age, socioeconomic determinants of health, and other medical conditions—to compare the drug’s effects accurately.

Among 22,572 patients with diabetes treated with insulin, there were 167 cases of CRC. Another 22,572 matched patients treated with GLP-1 RAs saw 94 cases of CRC. Those treated with GLP-1 RAs had a 44 percent reduction in CRC incidence.

Similarly, 18,518 patients with diabetes treated with Metformin when compared to 18,518 patients with diabetes treated with GLP-1 RAs, had a 25 percent reduction in CRC. “The research is critical for reducing the incidence of CRC in patients with diabetes, with or without overweight and obesity,” Berger said.

- This press release was originally published on the New Case Western Reserve University website