Background Numerous studies indicate that tissue factor (TF),namely tissue thromboplastin,has a close relationship with malignant tumor genesis and progress.It contributes to blood coagulation as well as the regulation of cellular differentiation,the formation of blood vessels,and also tumor recurrence and metastasis.The present study aimed to detect TF expression in hepatocellular carcinoma (HCC) patients and to elucidate its association with prognosis and clinical features of the disease.Methods The plasma TF levels of 50 HCC patients and 30 controls were assayed by ELISA.The expressions of TF mRNA and protein in HCC tissues,adjacent tissues and normal tissues were detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blotting.The acquired data were analyzed with related clinic-pathological documents.The patients were followed up for five years,and the relationship between TF and prognosis was analyzed.Results The plasma TF levels were significantly increased in HCC compared to the controls (P ＜0.05),presenting a close relationship with differentiation level,tumor size and hepatocirrhosis occurrence (P ＜0.05).There were remarkably higher values in cases of lymphatic metastasis,extrahepatic metastasis and portal tumor thrombus (PTT) (P ＜0.05)compared to non-metastasis or non-tumor thrombus,but no significant difference with different focus number or envelope (P ＞0.05).The positive rates and the relative expression of TF mRNA in HCC tissue were 63.0％ (17/27) and 0.567:±0.268,respectively,significantly higher than that in adjacent tissues or normal tissues (P ＜0.05).In the patients with positive results,the relative expression intensity varied significantly with different tumor size and index of local invasion and metastasis (P ＜0.05).The positive rates and the relative expression intensities of TF protein in HCC tissue were 74.1％ (20/27) and 4.093±1.256,respectively,significantly higher than those in adjacent tissue or normal tissue (P＜0.05).In the patients with positive results,the relative expression intensity showed significant difference in different tumor size,differentiation level,and index of local invasion and metastasis (P＜0.05).Conclusions The TF levels were significantly higher in plasma and tissues of HCC patients,presenting a close relationship with the index of invasion and metastasis.It indicated that TF might be related to differentiation and metastasis of HCC.