Expression of the adipocytokine resistin and its association with the clinicopathological features and prognosis of pancreatic ductal adenocarcinoma

Fat tissue is viewed as an active endocrine organ that secretes a variety of bioactive substances. Resistin, an adipocyte-secreted factor, is thought to be closely related to obesity, insulin resistance and inflammation, the three most significant risk factors for the progression of pancreatic cancer. However, the association between resistin and pancreatic cancer is still unknown. In this study, pancreatic tumor samples from 45 patients with pancreatic ductal adenocarcinoma were analyzed with immunohistochemistry for the expression of resistin. The correlation between resistin expression and clinicopathological features and prognosis were evaluated. Resistin staining was observed in 48.9% (22 of 45) of the cases. Resistin expression was more frequent in poorly differentiated tumors (9 of 9, 100%) compared to moderately differentiated tumors (11 of 28, 39.3%) and well-differentiated tumors (2 of 8, 25%) (p<0.01). The incidence of resistin expression in patients with Japan Pancreas Society stages III-IV (18 of 27, 66.7%) was significantly higher than in subjects with stages I-II (4 of 18, 22.2%) (p<0.01). Patients with resistin-stained tumors had significantly shorter relapse-free survival times (median, 9 months) than patients with negative tumors (median, 18 months) (p<0.05). In addition, multivariate analysis showed that resistin expression was an independent prognostic factor for relapse-free survival of patients with pancreatic ductal adenocarcinoma (p<0.05). These results demonstrate that resistin may influence the progression of pancreatic tumors and may be a useful predictor of relapse-free survival in patients with pancreatic ductal adenocarcinoma.