Postoperative Prognostic Predictors of Bile Duct Cancers: Clinical Analysis and Immunoassays of Tissue Microarrays.

Abstract

Cholangiocarcinoma frequently recurs even after curative resection. Expression levels of proteins such as epidermal growth factor receptor (EGFR), Snail, epithelial cadherin (E-cadherin), and interleukin-6 (IL-6) examined by immunohistochemistry have been studied as potential prognostic factors for cholangiocarcinoma. The aim of this study was to investigate significant factors affecting the prognosis of resectable cholangiocarcinoma. Ninety-one patients who underwent surgical resection at Samsung Medical Center for cholangiocarcinoma from 1995 to 2013 were included in this study. Expression levels of E-cadherin, Snail, IL-6, membranous EGFR, and cytoplasmic EGFR were analyzed by immunohistochemistry using tissue microarray blocks made from surgical specimens. Patients with high levels of membranous EGFR in tissue microarrays had significantly shorter overall survival (OS) and disease-free survival (DFS): high membranous EGFR (score 0-2) 38.0 months versus low membranous EGFR (score 3) 14.4 months (p=0.008) and high membranous EGFR (score 0-2) 23.2 months versus low membranous EGFR (score 3) 6.1 months (p=0.004), respectively. On the other hand, E-cadherin, Snail, cytoplasmic EGFR, and IL-6 did not show significant association with OS or DFS. Patients with distant metastasis had significantly higher IL-6 levels than those with locoregional recurrence (p=0.01). This study showed that overexpression of membranous EGFR was significantly associated with shorter OS and DFS in surgically resected bile duct cancer patients. In addition, higher IL-6 expression was a predictive marker for recurrence in cholangiocarcinoma patients with distant organ metastasis after surgical resection.