The potential of plasma thrombomodulin as a biomarker of portal vein tumor thrombus in hepatocellular carcinoma

Purpose: To study the relationship between thrombomodulin (TM) plasma levels and the formation of portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma (HCC). Methods: Pre- and postoperative plasma TM levels of 45 patients with HCC and six patients with benign liver-occupying lesion were measured by enzyme-linked immunosorbent assay (ELISA), and the expression of TM in human HCC tissues was determined by immunohistochemistry assay. Results: The preoperative plasma TM level of patients with HCC (10.2 +/- 5.7 ng/ml) was significantly higher than that of those patients with benign liver-occupying lesion (6.1 +/- 2.2 ng/ml) and that of normal controls (5.7 +/- 1.0 ng/ml), respectively (P < 0.05). The postoperative TM level of 40 patients with HCC whose tumors had been removed decreased significantly than the preoperative TM level (10.8 +/- 5.3 ng/ml versus 7.6 +/- 4.2 ng/ ml, P < 0.05), whereas there was no significant difference between the preoperative and postoperative TM level of six patients with benign liver-occupying lesion (6.1 +/- 2.2 ng/ml versus 5.9 +/- 1.8 ng/ml, P > 0.05). The preoperative plasma TM level of patients with single HCC (11.5 +/- 5.9 ng/ml) or no PVTT (11.4 +/- 5.6 ng/ml) was significantly higher than that of those patients with multiple HCC (8.1 +/- 4.6 ng/ml) or PVTT (6.9 +/- 4.5 ng/ ml), respectively (P < 0.05). The preoperative plasma TM level of the patients with HCC tissue that stained positive for TM was significantly higher than those with tissue that stained negative for TM (12.2 +/- 6.5 ng/ ml versus 8.7 +/- 4.6 ng/ml, P < 0.05). The postoperative plasma TM level showed no difference between the patients with HCC tissue stained positive and negative for TM (8.3 +/- 4.1 ng/ml versus 7.6 +/- 4.4 ng/ml, P > 0.05). There was also no significant difference between the plasma TM level and other clinicopathological futures. Conclusions: Plasma TM increases in patients with HCC and can be a biomarker of the formation of PVTT.