Expression of tumor stem cell marker EpCAM in patients undergoing liver transplantation for hepatocellular carcinoma and its relationship with tumor recurrence and metastasis

Abstract

Objective To investigate the expression of EpCAM (epithelial cell adhesion molecule) in patients undergoing liver transplantation for hepatocellular carcinoma (HCC), and to explore the relationship between EpCAM expression level and HCC recurrence. Methods 83 HCC tissue samples were collected and analyzed retrospectively. EpCAM was detected by immunohistochemistry staining and the correlation between EpCAM and clinicopathological features, prognosis and recurrence were analyzed retrospectively from patients undergoing liver transplantation in Peking University People′s Hospital from 2000 to 2010. Results Log-rank univariate survival analysis showed that the 5-year overall survival (41.2% vs. 73.3%, χ2=4.935, P=0.026)and 5-year disease free survival(41.2% vs. 73.3%, χ2=4.634, P=0.031)of HCC patients with high EpCAM expression level was significantly lower than that with low expression level of EpCAM. COX multivariate survival analysis showed patients with high EpCAM expression had a higher risk of recurrence(HR=2.860, 95%CI: 1.012-8.083) and death (HR=2.909, 95%CI: 1.030-8.217)after liver transplantation than those with low EpCAM expression, which was an independent predictor of 5-year overall survival and 5-year disease free survival recurrence (P=0.044). Furthermore, EpCAM expression level was highly related to tumor distant metastasis(P=0.01). Conclusion There was positive relation between high expression of EpCAM and high HCC recurrence after liver transplantation, suggesting that EpCAM can be a predictor for HCC recurrence and long-term survival of patients with HCC after transplantation. Key words: Liver transplantation; Cell adhesion molecules; Survival analysis; Recurrence