Clinicopathologic correlation of beclin-1 expression in pancreatic ductal adenocarcinoma

Beclin-1 has emerged as an autophagy gene in a variety of human carcinomas. The aim of this study was to evaluate beclin-1 expression and to determine its prognostic significance in patients with pancreatic ductal adenocarcinoma (PDA). We performed immunohistochemical staining for beclin-1 in 63 cases of PDA. We investigated whether beclin-1 expression correlated with clinicopathologic characteristics and patient outcomes. Beclin-1 expression was absent in normal pancreatic islet cells, acinar cells, and ductal epithelial cells. In contrast, in PDA, beclin-1 showed positive immunoreactivity in 14 of 63 (22.2%) PDA cases, while the remaining 49 (77.8%) PDA cases exhibited negative beclin-1 expression. We found significant associations between increased beclin-1 expression and the absence of lymphatic invasion (P = 0.032) and low rate of distant metastasis (P = 0.001). Univariate analysis of survival showed that the median distant metastasis-free survival of beclin-1-negative PDA patients (10 months) was significantly shorter than that of beclin-1-positive PDA patients (21 months; P = 0.031). Our results suggest that increased beclin-1 expression plays a role in the inhibition of PDA progression.