Clinical significance of serum HGF and c-Met expression in tumor tissue for evaluation of properties and treatment of hepatocellular carcinoma

BACKGROUND/AIMS: To develop a prognostic marker for evaluation of intrahepatic metastasis (IM) of hepatocellular carcinoma (HCC), the ligand-stimulated receptor activity of c-Met due to hepatocyte growth factor (HGF) was estimated. METHODOLOGY: For specimens from 30 HCC patients, who were operated on at the Department of Surgical Oncology, Gifu University School of Medicine, for 2 recent years, the induction value of HGF and c-Met were estimated by western blot. RESULTS: Firstly, the serum HGF levels were significantly higher in invasive gross type or in IM-positive tumors. Secondly, the mean expression value of HGF protein in tumors was 0.56 +/- 0.35, which was not different from non-tumor tissue, 0.59 +/- 0.40. And there was no significant differences based on tumor profiles. Thirdly, the value of c-Met in tumor tissue, 1.36 +/- 0.12, was clearly higher than in non-tumor tissue, 1.07 +/- 0.06. The c-Met expressions were significantly higher in the invasive type of HCC as determined by gross type, vessel invasion, IM presence and histological type. Finally, in individual studies about the relationship between the level of serum HGF and c-Met expression in tumor tissue, the presence of IM could be easily detected. Furthermore, the level of serum HGF after hepatectomy was significantly higher than the preoperative value, and individual studies with c-Met expression were associated with early recurrence. CONCLUSIONS: The induction of c-Met might be important to evaluate the progression of HCC, especially to caution for the presence of IM.