High expression of long non‐coding HOX antisense transcript RNA and its clinical significance in cancer tissues: A meta‐analysis

BACKGROUND HOX antisense transcript RNA (HOTAIR) is a 2148 nt long, intergenic, non-coding RNA molecule, which is reported to be highly expressed in many types of cancers. This meta-analysis summarizes its expression in cancer. METHODS We searched all eligible papers on the prognostic impact of HOTAIR in cancer from inception to 30 September 2015 in PubMed, CBMdisc, and the CNKI database. Only full texts were included. Revman 5.3 was used for meta-analysis. RESULTS A total of 11 studies of 1010 cases were included in the meta-analysis. HOTAIR expression was higher in: cancer tissues in than adjacent or normal tissues (odds ratio [OR] 37.52, 95% confidence interval [CI] 18.94-74.31; P  < 0.00001); in cancer tissues with lymph node metastasis than in those without lymph node metastasis (OR 3.37, 95% CI 2.36-4.82; P  < 0.00001); and in histological grades II-III than in histological gradeI(OR 0.47, 95% CI 0.29-0.75; P  = 0.002). CONCLUSION This study shows that HOTAIR may play an important role in cancer occurrence and development, but whether it is a marker of cancer diagnosis and reliable prognosis remains to be confirmed. More rigorous design and meticulous quality epidemiological studies are required.