Introduction: HOX transcript antisense intergenic RNA (HOTAIR), a long non-coding RNA transcribed from the antisense strand of the HOXC gene locus, has been reported to be overexpressed in various carcinomas and is thought to be an indicator of poor prognosis.
Evidence acquisition: We performed a meta-analysis using qualified relevant literatures to evaluate the prognostic significance of HOTAIR in various solid tumors. Eligible studies were identified from PubMed, EMBASE and ISI Web of Science through multiple search strategies. We extracted and estimated the hazard ratios (HRs) for overall survival (OS), which compared the high and low expression levels of HOTAIR in patients with a variety of solid carcinomas. HRs and 95% confidence intervals (95% CIs) were calculated to pool the effect size.
Evidence synthesis: A total of 2407 patients from 21 studies with various solid carcinomas were included. For OS, higher HOTAIR expression could significantly predict worse outcome with the pooled HR of 2.21 (95 % CI 1.77-2.74, P<0.00001). The subgroup analysis suggested that the elevated levels of HOTAIR appears to be worse OS in Asian population (HR=2.06, 95% CI 1.80-2.37, P<0.00001) and digestive system cancers (HR=2.27, 95% CI 1.93-2.67, P<0.00001) including esophageal squamous cell carcinoma (HR=2.27, 95% CI 1.62-3.18, P<0.00001) and colorectal cancer (HR=4.65, 95 % CI 2.39-9.05, P<0.00001).
Conclusions: The present meta-analysis revealed that the high level of HOTAIR is associated with an adverse OS in numerous solid cancers, suggesting that HOTAIR may be a predictor of poor prognosis for the development of solid tumors.