First human study links certain diabetes drugs to pancreatic cancer risk

Kathleen Blanchard's picture
Byetta, Januvia again linked to risk for pancreatic cancer in first human study.

Are you taking medications for type 2 diabetes? For the first time, researchers link pancreatic cancer risk to a popular class of anti-diabetic drugs that has now been found to cause abnormal tissue growth in the pancreas of humans. Past studies found the link in animals.

The drugs that treat diabetes are in the incretin class of anti-diabetic medications.

Animal studies showing potential harm to the pancreas have been mixed regarding the drugs.

This time researchers looked at humans treated with the drugs, finding possible increased risk neuroendocrine tumors from abnormal cell growth in the organ that secretes insulin and is important for digestion.

UCLA and the University of Florida scientists published their findings in the journal Diabetes, March 22, 2013.

In the newest study, the scientists found cell mass was increased approximately 40 percent in organ donors treated with the drugs.


Among 8 deceased organ donors, seven had been taking sitagliptin, sold as Januvia and marketed by Merck, and 1 donor had been taking exenatide, sold as Byetta by Bristol-Myers Squibb.

The drugs, along with others that provide GLP-1 or glucagon-like peptide 1 – based therapies are currently under investigation by the FDA because they have been possibly linked to pancreatitis and pancreatic cancer. The anti-diabetic drugs work by targeting GLP-1 hormones in the gut.

“There is an increasing appreciation that animal studies do not always predict findings in humans," said Dr. Peter Butler, director of UCLA's Hillblom Islet Research Center and chief of the endocrinology, diabetes and hypertension unit” in a press release, making the human study more significant.

Specific findings include larger pancreas from incretin class of anti-diabetic drugs that the researchers note was the result of increased cell growth.

Patients taking the drugs had abnormal cells or cell dysplasia which is a risk factor for pancreatic cancer in addition to expansion of alpha cells that make the hormone glucagon that is the opposite of insulin and raises blood sugar levels.

The study is the first to link abnormal cell growth in the pancreas of humans to the diabetes drugs that raises the risk of pancreatic cancer.

March 26, 2013

Image credit: Wikimedia commons