Metformin Hydrochloride in Treating Patients With Pancreatic Cancer That Can be Removed by Surgery

Inclusion Criteria: * Patients must have histologically or cytologically confirmed resectable pancreatic carcinoma; patients with pancreatic neuroendocrine tumors are not eligible * Patients must be previously untreated with chemotherapy or radiation therapy * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Patients must have surgical resection of the pancreas planned, with enrollment at least 7 days prior to surgery; patients with surgery scheduled \> 15 days will not be excluded * Hemoglobin (Hg)A1C must be below 7% * Total bilirubin less than 1.5 X institutional upper limit of normal * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\]) =\< 2.5 X institutional upper limit of normal * Alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) =\< 2.5 X institutional upper limit of normal * Serum creatinine within normal institutional limits * Alkaline phosphatase \< 1.5 X institutional upper limit of normal * Subjects must have the ability to understand and be willing to provide written informed consent Exclusion Criteria: * History of metformin use in the previous 3 months * Treatment with neoadjuvant chemotherapy or radiation therapy * History of allergic reactions attributed to metformin * Patients with uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements * Metabolic acidosis, acute or chronic, including ketoacidosis * Metastatic disease