Increased Serum Insulin Exposure Does Not Affect Age or Stage of Pancreatic Adenocarcinoma Diagnosis in Patients with Diabetes Mellitus

Objectives In considering whether medications that increase insulin levels accelerate pancreatic adenocarcinoma (PC) development, we hypothesized that PC patients with diabetes mellitus (DM) who used exogenous insulin or insulin-stimulating medications should have an earlier age at diagnosis or present with more advanced disease. Methods Patients enrolled in our PC registry from June 1, 2003, to May 31, 2012, were stratified according to treatment solely with insulin, insulin-stimulating medications, or insulin-independent medications. Age at PC diagnosis, PC stage, and years between DM and PC diagnoses were analyzed among the cohorts. Results Of 122 DM patients (mean age, 67.4 ± 10.2 years), the mean ages at PC diagnosis within the insulin-only (n = 40), insulin-stimulating (n = 11), insulin-independent (n = 71), and non-DM (n = 321) cohorts were 68.7 ± 10.5, 69.6 ± 10.8, 66.3 ± 9.7, and 65.5 ± 10.5 years, respectively. No significant difference among the age at PC diagnosis was observed based on duration or type of DM treatment. There was no correlation between PC stage and increased insulin exposure. Conclusions Anti-DM medications that increase exposure to insulin do not appear to accelerate PC development using outcomes of mean age at PC diagnosis, PC stage, or duration between DM and PC diagnoses.