Clinicopathological characteristics and liver stem cell marker expression in hepatocellular carcinoma involving bile duct tumor thrombi

The aim of this study was to analyze the clinicopathological characteristics and expression of liver stem cell markers of hepatocellular carcinoma (HCC) involving bile duct tumor thrombi (BDTT). A total of 35 patients with HCC and BDTT in a consecutive series of HCC patients who underwent surgical treatment were studied retrospectively and compared with 916 patients without BDTT from the same series. Clinicopathological characteristics, overall survival (OS), and tumor expression of liver stem cell markers CD133, CD90, EpCAM, CK19, VEGF, and C-kit were compared between the two patient groups. Analysis was performed for the entire patient groups as well as for 35 pairs of patients with or without BDTT matched by propensity score. HCC patients with BDTT tended to have smaller tumors than those without BDTT, as well as a higher probability of having poorly differentiated tumor, Child-Pugh class B, liver cirrhosis, and microvascular invasion. Tumor tissue in patients with BDTT showed significantly higher expression rates of all liver stem cell markers examined. OS was significantly lower for patients with BDTT at 1 year (69 vs 84 %), 3 years (37 vs 64 %), and 5 years (20 vs 55 %) (P<0.001). Patients with HCC and BDTT show lower OS than patients without BDTT. The higher frequency of liver stem cell marker expression in the presence of BDTT suggests that such stem cells may play a role in the pathogenesis of this form of HCC.