A recent preliminary study suggests that people taking the prescription drugs Januvia (sitagilptin) or Byetta (exenatide) to treat Type 2 diabetes may be at an increased risk of developing pancreatitis as well as pancreatic cancer.

In addition, the study discovered that Byetta could potentially increase risk of developing thyroid cancer. The researchers commented noted that the results weren’t conclusive and that further investigation would be necessary before a definite link could be identified.

“We have raised concern that there may be a link, but we haven’t confirmed it,” says Dr. Peter Butler, lead researcher on the project and the director of the Larry L. Hillblom Islet Research Center at the University of California in Los Angeles. “We need to do more work to figure out whether this is real or not,” continued Dr. Butler.

Byetta and Januvia are prescribed to Type 2 diabetics to help keep blood glucose levels in a healthy range. The medications encourage the production of a hormone called glucagon-like peptide 1 (GLP-1).

Although Januvia and Byetta, both relatively new injectable drugs that treat Type 2 diabetes, have some benefits over older medications, Dr. Butler warns that every new medication requires thorough research to determine any complications that could arise from its use. “When new drugs come out, the long-term side effects of these drugs are not well understood,” said Dr. Butler.

Dr. Butler’s team used data from the U.S. Food and Drug Administration’s database of adverse events in patients taking Byetta and Januvia between 2004 and 2009. Any time a patient experiences an adverse event, it is reported by the patient’s physician and recorded in the database.

Dr. Butler’s team found that patients who were being treated with Byetta and Januvia displayed six times more reported cases of pancreatitis. Those taking Byetta showed a 2.9-fold increase in pancreatic cancer while those taking Januvia showed a 2.7-fold increase in pancreatic cancer. The researchers also noted that there was an increase in reported cases of thyroid cancer among patients prescribed Byetta.

However, Dr. Butler stated that the data does not necessarily point to an increase in those complications among patients taking the medications but could be a result of an increase in the number of doctors actually reporting those adverse events.

“It is important to avoid alarmism and have people stop medicines that they may be benefitting from when the risk is not yet defined,” said Dr. Butler. “If the drug and you are working well together, I wouldn’t say there is any reason to stop the drug, based on the evidence we have right now,” he said. “But if you have any concern you should talk to your doctor about it.” Butler also noted that losing weight is the greatest deterrent to pancreatic cancer in patients with Type 2 diabetes.

Dr. Mary Ann Banerji, director of the Diabetes Treatment Center at SUNY Health Science Center Brooklyn, New York City, agrees with Dr. Butler, stating that the data “should not be blown out of proportion.”

Dr. Banerji does not prescribe Byetta or Januvia to patients with a family history of thyroid cancer or pancreatitis, but other drugs such as metformin and insulin come with their own risks. “You prescribe them on an individual basis, because, in the end, all of medicine is individual,” said Dr. Banerji. “We should use these drugs judiciously along with metformin.