Introduction: Associations between diabetes mellitus (DM) and pancreatic ductal adenocarcinoma (PDAC) have been described. Outcomes for patients with PDAC and a co-morbid diagnosis of DM have not been clarified.
Methods: Records for all patients with PDAC resected between 1/1/2000 and 12/31/2005 were reviewed for patient, disease, and operative factors. Outcomes for patients with a preoperative diagnosis of DM (DM+) were compared to those who were not diabetic (DM-). Chi square testing and Student’s T-test were performed for all categorical and continuous variables respectively. Univariate analysis was performed for overall survival by Kaplan-Meier method and compared using log rank testing. Multivariate analysis (Cox regression) was performed for all factors approaching statistical significance (p < 0.1) on univariate testing.
Results: Adequate demographic, operative, histologic, and follow up data were available for 104 patients who underwent resection of PDAC between 2000 and 2005, 33 patients (32%) had documented history of DM and 20 were insulin dependent. Median age was 64 (range; 37-84), 49 (47%) were men, and average BMI was 26.7+5.6. Median tumor size was 3 cm (range; 1.5-9.0), 70 patients (67%) had node positive disease, and 19 patients (18%) had positive resection margins. There was no significant difference in age (62.7 vs 65.6), BMI (26.3 vs 27.5), margin positive resection rate (15% vs 24%), or node positive disease rate (68% vs 67%) for DM- and DM+ respectively. Diabetics had slightly larger tumors (4.0 vs 3.3 cm, p=0.04) and higher preoperative serum blood glucose measurements (189+78 vs 133+48 mg/dl, p<0.001). Overall median survival was 16 months (range; 0-50) and stratified by DM was 18 (DM-) vs 12 (DM+, p=0.003) months. On univariate analysis factors associated with reduced survival were age >65, tumor size >3.0 cm, node positive status, margin positive resection, and a history of DM+. On multivariate analysis, tumor size (RR, 1.7; 95% CI, 1.0-2.7), margin status (1.8; 1.0-3.2), and DM+ (1.8; 1.0-3.0) all maintained independent association with poor survival.
Conclusions: Diabetes mellitus is independently associated with reduced survival in patients undergoing resection for pancreatic ductal adenocarcinoma. Mechanisms for reduced survival in DM+ patients undergoing resection of PDAC should be investigated further.