miR-21 expression predicts prognosis in hepatocellular carcinoma.

Purpose: The aim was to investigate the expression level of miR-21 in HCC tissues and its prognostic value among Asian population.

Methods: In the present study, expression of miR-21 was evaluated by qRT- PCR in tumor and adjacent non-neoplastic tissues in 119 HCC patients. The association of miR-21 expression with clinicopathological factors and the prognosis of HCC patients was also analyzed. Survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model.

Results: We found that miR-21 expression was significantly higher in HCC tissues compared with normal adjacent liver tissues (P<0.0001). The 5-year overall survival (OS) of high miR-21 expression group was significantly shorter than that of low miR-21 expression group (40.2% vs. 70.7%; P=0.007). Moreover, the 5-year disease-free survival (DFS) of high miR-21 expression group was also significantly shorter than that of low miR-21 expression group (17.4% vs. 57.3%; P=0.001). Furthermore, in a multivariate Cox model, we found that miR-21 expression was an independent poor prognostic factor for both 5-year OS (hazards ratio [HR]=3.189, 95% confidence interval [CI]=1.911-10.012, P=0.03) and 5-year DFS (HR=5.897, CI=3.009-13.763, P<0.001) in HCC.

Conclusions: The results of the present study suggested miR-21 expression level could be a novel potential biomarker for HCC prognosis.