Systematic Review and Meta-Analysis: Circulating miRNAs for Diagnosis of Hepatocellular Carcinoma.

Because early-stage hepatocellular carcinoma (HCC) is difficult to diagnose using the existing techniques, identifying better biomarkers would likely improve the patients' prognoses. We performed a systematic review and meta-analysis of published studies to appraise the utility of microRNAs (miRNAs) for the early diagnosis of HCC. Pertinent literature was collected from the Medline, Embase, and Chinese National Knowledge Infrastructure databases. We analyzed 50 studies that included 3423 cases of HCC, 2403 chronic hepatic disease (CH) patients, and 1887 healthy controls in 16 articles. Summary receiver operating characteristic analyses of all miRNAs showed an area under the curve (AUC) of 0.82, with 75.8% sensitivity and 75.0% specificity in discriminating patients with HCC from healthy controls. miR-21 and miR-122 individually distinguished patients with HCC from healthy controls, with an AUC of 0.88 for miR-21 and 0.77 for miR-122. The sensitivity and specificity for miR-21 were 86.6% and 79.5%, respectively, those for miR-122 were 68.0% and 73.3%. We conclude that circulating miRNAs, particularly miR-21, and miR-122, are promising biomarkers for the early diagnosis of HCC.