BTG1 low expression in pancreatic ductal adenocarcinoma is associated with a poorer prognosis

Abstract

BTG1 is a member of the TOB/BTG protein family, which is a transducer of ErbB-2 and TOB2. It is known to inhibit tumor genesis, but its role in pancreatic ductal adenocarcinoma (PDAC) is still unknown. The purpose of this study is to investigate the expression of BTG1 protein in PDAC and to determine its prognostic significance. Immunohistochemistry is used to determine the protein expression of the BTG1 gene in 79 surgically resected PDAC. The association of BTG1 expression with all the patients' clinicopathologic parameters, including survival, was analyzed using statistical software. High BTG1 expression was observed in 27.8% (22/79) of the PDAC tissues, which was significantly lower than the 58.2% (46/79) of corresponding normal adjacent noncancerous tissues by immunohistochemical staining (p<0.001).Through the stratified analysis, we found a significant difference of BTG1 expression in peri-neural invasion (p = 0.002), T stage (p = 0.000), N stage (p = 0.018), and tumor, node, and metastasis stage (p = 0.000). Univariate and multivariate Cox analysis revealed that BTG1 expression status was an independent prognostic factor in PDAC (p = 0.027). Moreover, overall survival was better in PDAC cases with higher rather than lower BTG1 expression (p = 0.027). This study demonstrated for the first time that lower expression of BTG1 might be involved in the progression of PDAC, suggesting that BTG1 might be a novel prognostic marker and a target for therapy.