Among patients with pancreatic adenocarcinoma, those with pre-existing type 2 diabetes mellitus for longer than five years have an increased mortality risk, according to a study published online Aug. 1 in Cancer.

(HealthDay) -- Among patients with pancreatic adenocarcinoma (PAC), those with pre-existing type 2 diabetes mellitus (T2DM) for longer than five years have an increased mortality risk, according to a study published online Aug. 1 in Cancer.

To assess the effect of varying durations of pre-existing T2DM on survival, Allen Hwang, M.D., of the University of Pennsylvania in Philadelphia, and colleagues conducted a using data from The Health Improvement Network medical record database (2003 to 2010) for 3,147 patients with PAC. Of these, 745 had pre-existing T2DM and 2,402 did not.

In the primary analysis, the researchers found that there was no survival difference for those with and without pre-existing T2DM (hazard ratio, 1.02; P = 0.620). In a secondary analysis, significantly increased mortality was seen for patients with T2DM of more than five years duration (hazard ratio, 1.16; P < 0.05).

"In summary, we observed a significant increase in overall mortality in patients with a long-standing duration of T2DM (greater than five years)," the authors write. "The implications of these results are magnified by the growing prevalence of diabetes mellitus, the incidence of which has been increasing over the past two decades and is expected to nearly double over the next 25 years."