Older Americans with new-onset diabetes have high risk of pancreatic cancer

In a groundbreaking population-based study, researchers in Mayo Clinic Cancer Center found that new onset of hyperglycemic diabetes in adults age 50 or older may be a signal of underlying pancreatic cancer. The risk of developing the cancer within three years after a new diagnosis of diabetes is eight times higher than for the average same-age individual. The findings will be published in the Aug. 1 issue of Gastroenterology.

“Pancreatic cancer is difficult to detect until it is in an advanced stage, leaving little hope for patients,” says Suresh Chari, M.D., Mayo Clinic gastroenterologist and lead investigator of the study. “This study is important, because it leads us closer to finding indicators that will allow earlier detection and treatment.”

Pancreatic cancer is a deadly disease – nearly all patients die – that claims 32,000 lives in the United States each year and has an equal number of diagnoses annually. Patients with this type of cancer seldom exhibit disease-specific symptoms until the cancer is at an advanced stage, and two major obstacles prevent physicians from making an early diagnosis. First is the lack of a high-risk group – a population of individuals, other than rare genetic disorders, in whom pancreatic cancer is common; and second is a lack of a PSA-like blood test for pancreatic cancer. Dr. Chari and his team’s study shows that new-onset diabetes defines a high-risk group for pancreatic cancer.

While the study showed that about 1 percent of patients who met fairly stringent criteria for diabetes developed pancreatic cancer within three years, in most patients the cancer was at an advanced stage at diagnosis. Because patients in this study had not been screened for diabetes or pancreatic cancer, Dr. Chari’s team was looking at those diagnosed after the fact. “Our goal now is to identify a marker in the blood that will enable us to distinguish diabetes associated with pancreatic cancer from the far more common type 2 diabetes,” said Dr. Chari, “so we are able to screen patients with new-onset diabetes to detect pancreatic cancer before it spreads.”

The study population of 2,122 patients was drawn from the Rochester Epidemiology Project and included all residents age 50 or older of Rochester, Minn., between 1950 and 1995. Comparison to the general populace was made using data from the Iowa Surveillance, Epidemiology and End Results (SEER) program.