Studies Find Link Between Pancreatic Cancer and Diabetes

The onset of diabetes among those over the age of 50 can be a precursor to the development of pancreatic cancer, according to the results of two related studies, both published in the May 23, 2018 issue of the journal Gastroenterology.

Approximately 1% of those over the half century mark with new-onset diabetes (based on glycemia) are diagnosed with pancreatic cancer within three years, according to gastroenterologist Suresh Chari, MD, professor of Medicine with the Mayo Clinic College of Medicine in Rochester, Minnesota, and an author of the studies.

“Currently, pancreatic cancer is diagnosed at a very late stage when there’s not much to offer,” he says. “But our studies provide hope that pancreatic cancer can indeed be diagnosed at an earlier stage when resectable.”

In the first study, researchers plotted blood sugars levels of patients with pancreatic cancer going back five years prior to diagnosis. Researchers also plotted the blood sugars of a control group of patients who were age and gender matched to the patients with pancreatic cancer. In this group, researchers were able to show that blood sugars rise 30 to 36 months before the diagnosis of cancer.

In another group of patients and controls, researchers plotted blood sugars of nearly 600 patients with pancreatic cancer just prior to surgical removal of the cancer. Researchers grouped these patients by their tumor volume at the time of the surgical removal.

In the second study, Mayo researchers describe a risk-prediction model that identifies patients with new onset diabetes that are at very high risk for developing pancreatic cancer. Researchers say the findings are significant because they represent a potential new way to diagnose pancreatic cancer at an earlier stage.

The model, called an ENDPAC score, identifies a subset of patients with new onset diabetes that have a thirty to forty-fold higher risk of having pancreatic cancer.

Providers weigh in

“It's interesting work,” says Brandon Smaglo, MD, an oncologist at the Baylor College of Medicine in Houston. “Pancreas cancer’s still one of the nuts that we've not been able to crack in the cancer world; primarily because we find it late.” The researchers, Smaglo continued, are using a relatively ordinary blood [glucose level] test to help find it earlier. “Its simplicity means there’s no added cost to patients.”

Alan Feldman, MD, an endocrinologist at Jupiter Medical Center in Jupiter, Florida, believes both studies are limited.

“Both studies are retrospective,” he says. “The first is simply trying to assess how long people have had diabetes prior to the diagnosis of pancreatic cancer; it’s not a study that would help diagnose pancreatic cancer.”

The second study’s purpose, continued Feldman, was to try to identify a set of risk factors that could indicate a higher risk for having underlying pancreatic cancer as the cause for diabetes. “If they were able to accomplish this, presumably, they could pick up patients with pancreatic cancer at an earlier stage.”

Retrospective studies like this are only useful if they lead to prospective studies that demonstrate differences in healthy outcomes or costs, says Feldman. “This study doesn’t do that.”