Prognostic value of microRNAs in osteosarcoma: a meta-analysis

BACKGROUND: Osteosarcoma is the most common primary bone malignancy. We meta-analyzed the prognostic value of altered miRNAs in patients with osteosarcoma. METHODS: Sources from MEDLINE (from inception to August 2016) and EMBASE (from inception to August 2016) were searched. Studies of osteosarcoma with results of miRNA and studies that reported survival data were included and two authors performed the data extraction independently. Any discrepancies were resolved by a consensus. The outcome was overall survival and event-free survival assessed using hazard ratios (HRs). RESULTS: After reviewing the full text of 65 articles, 25 studies including 2,278 patients were eligible in this study. The pooled HR for deaths was 1.40 (95% confidence interval [CI] 1.01-1.94, p=0.04) with random-effects model (χ(2)=113.08, p<0.00001, I(2)=79%) for patients of osteosarcoma with lower expression of miRNA. However, the pooled HR for events was not significant (HR 0.97, 0.63-1.48, p=0.87, χ(2)=72.65, p<0.00001, I(2)=79%). In pathway analysis of miRNAs, miRNA449a, 199-5p, 542-5p have common target genes. CONCLUSIONS: Expression level of miRNA in patients of osteosarcoma is important as a prognostic factor.