Sulfonylureas (not metformin) improve survival of patients with diabetes and resectable pancreatic adenocarcinoma

Patients with pancreatic adenocarcinoma have an increased propensity for diabetes. Recent studies suggest patients with diabetes and pancreatic adenocarcinoma treated with metformin have increased survival. This study was undertaken to determine whether metformin use is associated with increased survival in patients with pancreatic adenocarcinoma. Patients who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma from 1991 to 2013 were included in this study. Survival was evaluated by Kaplan-Meier analysis. Median data are reported. Significance was accepted with 95% probability. Of 414 patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma, 132 (32%) were diabetic. Of patients with diabetes, 35 (27%) were diet-controlled, 34 (26%) were treated with insulin alone, 18 (14%) were treated with metformin alone, 14 (10%) were treated with sulfonylureas alone, 7 (5%) were taking sulfonylureas with insulin, and 24 (18%) patients were taking metformin with sulfonylureas and/or insulin. Patients with/without diabetes not taking sulfonylureas had survival of 16.4 months compared with patients taking sulfonylureas who achieved survival of 27.5 months after undergoing pancreaticoduodenectomy (P<0.05). Patients taking sulfonylureas with or without other therapy had improved survival compared with patients not taking sulfonylureas after pancreaticoduodenectomy. Metformin does not seem to be beneficial for patients with resectable disease, but may be beneficial for patients with unresectable and/or metastatic disease as shown in prior studies. The use of sulfonylureas is associated with a survival benefit for patients undergoing resection for pancreatic adenocarcinoma. Tumor staging and margin status continue to be the overriding predictors of survival in patients with resectable pancreatic adenocarcinoma, not metformin therapy.