Incidental Microscopic Bile Duct Tumor Thrombi in Hepatocellular Carcinoma after Curative Hepatectomy

In patients with hepatocellular carcinoma (HCC), the presence of bile duct tumor thrombi (BDTT) in the major bile ducts indicates poor prognosis compared with that of HCC patients without BDTT. However, the prognostic significance of incidental microscopic BDTT in the peripheral bile ducts after curative liver resection is not known. We compared the outcomes of HCC patients with and without microscopic BDTT in the peripheral bile ducts who underwent hepatectomy.The electronic medical records of 31 patients with microscopic BDTT (BDTT group) were retrospectively reviewed. To compare the surgical outcomes, 62 patients (No BDTT group) were randomly chosen from the remaining HCC patients without BDTT based on age, sex, etiology of HCC, tumor size, tumor number, and modified Union for International Cancer Control T staging.The 1-year, 2-year, and 3-year disease-free survival rates and overall survival rates were 54.8%, 34.0%, 34.0% and 90.1%, 69.2%, 61.0% in the BDTT group and 66.8%, 59.2%, 42.3% and 86.4%, 84.4%, 84.4% in the No BDTT group (P = 0.089 and P = 0.014, respectively). The overall survival curve in the No BDTT group was higher than that in the BDTT group. Multivariate analysis revealed that predisposing factors for tumor recurrence after curative liver resection included increased levels of the protein induced by vitamin K antagonist-II (PIVKA-II), tumor grades 3 and 4, and the presence of BDTT.This study demonstrates that HCC prognosis is worse in patients with incidental microscopic BDTT in the peripheral bile ducts than it is in those without BDTT. The presence of BDTT should therefore be considered when evaluating a patient's HCC prognosis after curative hepatectomy.