Insulin resistance is associated with the aggressiveness of pancreatic ductal carcinoma

Aims To study whether insulin resistance accelerates the development and/or the progression of pancreatic adenocarcinoma (PDAC), we hypothesized that patients with insulin resistance, compared with those without insulin resistance, show: (1) a younger age and more advanced PDAC stage at diagnosis and (2) a shorter disease-free and overall survival after PDAC diagnosis. Methods Prospective observational study of patients admitted to a referral center for pancreatic disease. Insulin resistance was defined as a HOMA-IR value greater than the 66th percentile value of the patients included in this study. Survival was estimated according to Kaplan-Meier and by Cox regression. Results Of 296 patients with PDAC, 99 (33 %) met criteria for being classified as insulin resistant at diagnosis. Median follow-up time after diagnosis was 5.27 +/- 0.23 years. Patients with insulin resistance received a diagnosis of PDAC at a similar age compared to patients without insulin resistance (67.1 +/- 9 vs. 66.8 +/- 10 years, p = 0.68), but were more likely to have a cancer stage >= 3 (23.2 vs. 14.2 %, p = 0.053) and a residual disease after surgery (R1 56.4 vs. 38 %; p = 0.007). The median overall survival was 1.3 +/- 0.14 and 1.79 +/- 0.11 years for the patients with and without insulin resistance, respectively (p = 0.016). Results did not change when patients with diabetes at PDAC diagnosis were excluded from the analysis. Multivariate analysis showed that insulin resistance was independently associated with overall survival. Conclusions Insulin resistance is associated with the aggressiveness of PDAC.