title: Type 2 diabetes mellitus and survival in pancreatic adenocarcinoma: a retrospective cohort study.
abstract: BACKGROUND
  Recent evidence has identified pre-existing type 2 diabetes mellitus (T2DM) as a risk factor for the development of PAC, but relatively little is known about its effects on survival. Our aim was to determine the effect of varying durations of pre-existing T2DM on survival in patients with PAC.
  
  
  METHODS
  We conducted a retrospective cohort study using The Health Improvement Network (THIN), a primary care electronic medical record database from the UK (2003-2010). The study cohort included all subjects with a diagnostic code for PAC. Subjects with a diagnostic code for T2DM before their PAC diagnosis were classified as exposed; otherwise, subjects were classified as unexposed. The primary outcome was overall survival. The analysis was performed using univariate and multivariable Cox proportional-hazards models. Additional analysis was performed to assess the effect of increasing duration of pre-existing T2DM [i.e., <90 days, 90 days to <1 year, 1 to <3 years, 3 to 5 years, >5 years] on survival.
  
  
  RESULTS
  The study included 3,147 patients with PAC, with 745 patients having pre-existing T2DM and 2,402 patients without pre-existing T2DM. In the primary multivariate analysis, there was no difference in survival between those exposed and those unexposed to pre-existing T2DM (HR 1.02 [0.93, 1.12], p = 0.620). In the secondary analysis, only those patients with T2DM > 5 years duration had a significantly increased mortality (HR 1.16 [1.00, 1.33], p < 0.05).
  
  
  CONCLUSIONS
  Long-term pre-existing T2DM is associated with increased mortality in patients diagnosed with PAC.
authors.affiliation: Department of Gastroenterology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Allen
authors.initials: A
authors.lastname: Hwang
authors.forename: Vivek
authors.initials: V
authors.lastname: Narayan
authors.forename: Yu-Xiao
authors.initials: YX
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000401:mortality*; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000401:mortality*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000209:etiology / Q000401:mortality*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors