Abstract:Objective To investigate the expression level of microRNA(miR)-449b in peripheral blood and its relationship with prognosis of patients with primary hepatocellular carcinoma(PHC).Methods A total of 98 PHC patients undergoing radical resection from January 2013 to January 2015 were selected as observation group,and 30 healthy examined people during the same period were served as control group.The quantitative real time polymerase chain reaction assay was used to detect the expression level of miR-449b in peripheral blood.The patients in observation group were followed up until October 2019 to observe the overall survival (OS) and analyze the association of miR-449b expression with OS.Results The expression level of miR-449b in observation group was significantly lower than that in control group （0.25±0.09 vs 0.59±0.12, t=16.674, P<0.01）.In the 90 followed patients,49 patients died.Kaplan-Meier combined with Log-rank test showed that OS in patients with low expression of miR-449b were significantly shorter than that in patients with high expression of miR-449b ( P<0.05).Cox analysis showed that lower miR-449b expression,older age and higher TNM stage were the independent risk factors for OS in PHC patients( P<0.05).Conclusion In patients with PHC,the down-regulation expression of miR-449b is associated with poor OS,and peripheral blood detection of miR-449b may be an effective prognostic marker of PHC.