Study findings offer hope of identifying new at-risk population for pancreatic cancer

Aug 2 2005

According to a study published in the American Gastroenterological Association (AGA) journal Gastroenterology, 1 in 120 people newly diagnosed with diabetes age 50 and older have a higher risk of developing pancreatic cancer - a risk that is eight times more than expected for the general population.

For years, there has been controversy over whether type 2 diabetes predisposes people to pancreatic cancer or if diabetes is an indicator of underlying pancreatic cancer. This is the first study to evaluate the importance of using age at diabetes diagnosis as an indicator for pancreatic cancer and suggests a new population to be tested for pancreatic cancer.

"Pancreatic cancer has a dismal prognosis because it is usually far advanced by the time people learn of their condition," said Suresh T. Chari, MD, lead study author. "Early diagnosis of pancreatic cancer is nearly impossible due to the lack of a known population at risk for the disease and an accurate screening test. We hope that our research leads to additional studies confirming that older people with newly diagnosed diabetes should be checked for pancreatic cancer."

Pancreatic cancer is the fourth-leading cancer killer in the United States and it is estimated that nearly 32,000 people will die in 2005 from the disease. Most often, the disease does not present symptoms and is usually detected in advanced stages. Only 23 percent of patients with pancreatic cancer survive more than a year after diagnosis and 4 percent survive for five years. Older Americans are at great risk for developing pancreatic cancer--almost all patients are over the age of 50. In addition, pancreatic cancer is more common in people with diabetes, with the greatest risk existing in the first five years after diagnosis. According to the American Diabetes Association, more than 18 percent of the U.S. population over the age of 60 has diabetes.

Researchers at the Mayo Clinic College of Medicine conducted a population-based study to evaluate the usefulness of using new-onset diabetes as an underlying marker for pancreatic cancer. The study population included 2,122 patients from Rochester, MN, aged 50 and older who were diagnosed with diabetes between 1950 and 1995. Of these, 18 were found to have pancreatic cancer within three years. Researchers compared these results with rates expected for people of similar age and sex without diabetes.

While study findings show that older patients have less than a 1 percent chance of having pancreatic cancer as the cause of their diabetes, they are still considered a high-risk group for developing the cancer. Between 55 and 65 percent of people with pancreatic cancer have hyperglycemia and diabetes. For these factors to be useful in establishing the need for screening in relatively asymptomatic patients, researchers say it is necessary to find the difference between pancreatic cancer-induced diabetes and type 2 diabetes.

"More research is needed to determine if using increased sugar levels as an indicator of pancreatic cancer is feasible," said Dr. Chari. "Future research has the potential to lead to a screening test for this 'silent killer' that quickly claims thousands of lives each year."