Altered long non-coding RNAs predict worse outcome in osteosarcoma patients: evidence from a meta-analysis

Long non-coding RNAs (lncRNAs) are emerging as promising prognostic biomarkers in an expanding list of malignant neoplasms. Here, we sought to investigate the strength of associations between lncRNA signatures and clinical outcomes in osteosarcoma. We conducted a systematic search of the online databases from inception to July 2016. Hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) for the primary endpoints of overall survival (OS), progression-free survival (PFS) or event-free survival (EFS) were extracted and meta-analyzed. Our results manifested that altered lncRNAs expression was markedly associated with worse OS (univariate analysis: HR = 3.20, 95% CI: 2.42-4.24, P = 0.000; multivariate analysis: HR = 2.66, 95% CI: 1.92-3.69, P = 0.000), PFS (HR = 2.05, 95% CI: 1.32-3.18, P = 0.001) and EFS (HR = 4.37, 95% CI: 1.64-11.66, P = 0.003) times among osteosarcoma patients. In the pooled analyses stratified by clinicopathological features, levels of lncRNAs were closely correlated with tumor size (pooled P = 0.001), tumor stage (pooled P = 0.003), and distant metastasis (pooled P = 0.002) in osteosarcoma. The results obtained in our work suggest that altered lncRNA signatures predict unfavorable clinical outcomes and are acceptable to be potential prognostic biomarkers in forecasting prognosis of osteosarcoma.