A survey of c-MET expression and amplification in 287 patients with hepatocellular carcinoma

Background: c-N-Methyl-N′-nitro-N-nitrosoguanidine HOS transforming gene (c-MET) is a new potential drug target for treatment of patients with hepatocellular carcinoma (HCC), and a recent study of a c-MET inhibitor in such patients has shown promising results. In the present study, we investigated the incidence of c-MET overexpression and its prognostic impact. Materials and Methods: Tumor tissue microarrays were used to detect the expression of c-MET in samples from 287 patients with HCC who underwent surgical resection at Samsung Medical Center. We explored the relationships between c-MET overexpression and clinicopathological features of HCC, and investigated recurrence-free survival (RFS) and HCC-specific survival according to the level of c-MET expression. Additionally, we explored the correlation between c-MET protein overexpression, and MET mRNA expression and copy number variation. Results: Most patients in the present study were male (n=297, 82.6%), with Child-Pugh class A liver function (n=286, 99.7%) and hepatitis B viral infection (n=217, 75.6%). c-MET overexpression was observed in 80 patients (27.9%), and was not associated with Edmondson grade, tumor size, microvascular invasion, major portal vein invasion or stage. In addition, c-MET expression levels did not affect RFS or HCC-specific survival. c-MET expression was weakly correlated with c-MET copy number variation (r=0.255, p<0.001), but more than half of all patients with c-MET overexpression had a neutral c-MET copy number. c-MET protein expression was very weakly but significantly positively correlated with its mRNA expression (r=0.199, p=0.002). Conclusion: c-MET overexpression did not have any prognostic impact on recurrence or survival of patients with HCC undergoing surgical resection. However, 27.9% of patients who had c-MET overexpression could be considered candidates for treatment with c-MET inhibitor.