Circulating stem cell-like epithelial cell adhesion molecule-positive tumor cells indicate poor prognosis of hepatocellular carcinoma after curative resection

Epithelial cell adhesion molecule–positive (EpCAM+) hepatocellular carcinoma (HCC) cells may constitute a tumor-initiating subpopulation in tumorigenic cell lines and HCC specimens. In the present study, EpCAM+ circulating tumor cells (CTCs) were identified prospectively in HCC patients undergoing curative resection, and the prognostic significance and their stem cell–like characteristics were investigated further. Blood samples from 123 HCC patients were tested prior to resection and 1 month thereafter. CTCs were present in 66.67% of patients, and the cell count measured in 7.5 mL of blood (CTC7.5) ranged between 1 and 34. Fifty-one patients had CTC7.5 of ≥2 preoperatively, and these patients developed tumor recurrence earlier than those with CTC7.5 of