Prognostic value of abnormally expressed long non-coding RNAs in patients with osteosarcoma: a meta-analysis

Abstract

Long non-coding RNAs (lncRNAs) contribute to progression of various cancers including osteosarcoma through abnormal regulation of cancer-related cellular processes. Recent researches have shown that various lncRNAs are abnormally expressed in osteosarcoma and associated with the prognosis. With the aim of gaining a better insight into the association between expression level of lncRNAs and prognosis of osteosarcoma, multiple databases including PubMed, Embase, Cochrane Library and Web of Science were carefully searched for available studies up to March 14, 2017. Finally, 19 publications with 1298 patients matched our inclusion criteria and were evaluated in our meta-analysis. The quality of each study was scored using the Newcastle-Ottawa Scale and studies not reaching a minimum threshold were excluded. Results of the meta-analysis demonstrated that abnormal expression level of lncRNAs predicted poor overall survival (pooled HR 3.064, 95% CI: 2.487–3.775) and event-free survival (pooled HR 2.642, 95% CI 1.759–3.970) in osteosarcoma and subgroup analysis showed consistent prognostic value. Furthermore, combining data of Cox multivariable analysis indicated that abnormal expression level of lncRNAs was an independent prognostic marker for overall survival (pooled HR 2.864, 95% CI: 2.246–3.651) in osteosarcoma patients. The clinicopathological parameters analysis further showed that abnormal expression level of lncRNAs was correlated with tumor size, tumor stage, metastasis and differentiation grade of osteosarcoma. Limitations of the meta-analysis included variation of cut-off value definition, Chinese provenance of most studies, publication bias and so on. In conclusion, this meta-analysis suggested that abnormal expression level of lncRNAs has a promising future for predicting the prognosis of patients with osteosarcoma.