Type 2 diabetes mellitus and survival in pancreatic adenocarcinoma

A retrospective cohort study

Authors

  • Allen Hwang MD MSCE,

    1. Department of Gastroenterology, University of Pennsylvania, Philadelphia, Pennsylvania
    Search for more papers by this author
  • Vivek Narayan MD,

    1. Department of Medicine, Hospital at the University of Pennsylvania, Philadelphia, Pennsylvania
    Search for more papers by this author
  • Yu-Xiao Yang MD MSCE

    Corresponding author
    1. Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania
    • Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, 423 Guardian Drive, 722 Blockley Hall, Philadelphia, PA 19104

    Search for more papers by this author
    • Fax: (215) 349-5915;


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. Cancer 2013. © 2012 American Cancer Society.

Ancillary