High expression level of long non-coding RNA HOTAIR is associated with poor overall survival in gastric cancer patients: evidence from meta-analysis.

PURPOSE Although several studies have investigated the association between the development of gastric cancer (GC) and the expression level of long non-coding (lnc) RNA HOTAIR, no clear evidence about whether its expression is associated with the overall survival (OS) of GC patients exists. In this study we tried to explore the association between lncRNA HOTAIR expression levels with OS and other clinical features in GC patients. METHODS Databases including PubMed, EMBASE and the Cochrane Library were used to search eligible studies. The quality of included studies was assessed according to reporting recommendations for tumor marker prognostic studies (REMARK). The association between the expression level of lncRNA HOTAIR and OS was evaluated by calculating the pooled hazard ratio (HR) and 95% confidence interval (95% CI) using the STATA software, version 12.0. RESULTS A total of 9 studies involving 740 GC and 768 normal gastric tissues were included in this meta-analysis. The average score of quality assessment was 18.89±1.08, (range 16.5-20). The results indicated that high expression levels of lncRNA HOTAIR were associated with poor OS in GC patients (pooled HR: 1.43, 95% CI:1.17-1.76, p=0.000). Subgroup analyses showed that elevated expression of lncRNA HOTAIR was significantly associated with poor OS in Chinese GC patients (HR=1.414, 95%CI: 1.120-1.785, p=0.000), and not treated GC patients (HR=1.464, 95%CI: 1.179-1.817, p=0.001). Subgroup analyses also revealed that some GC patients features (e.g. T3-T4, III/IV stage, differentiation) were associated with an unfavorable outcome. CONCLUSIONS High expression level of lncRNA HOTAIR is associated with a poor OS in GC patients. Thus, lncRNA HOTAIR might be a potentially useful independent prognostic biomarker for GC.