title: Prognostic value of long noncoding RNA HOTAIR in digestive system malignancies.
abstract: OBJECTIVE
  HOX transcript antisense intergenic RNA (HOTAIR), a well-known long noncoding RNA, has been found to play significant roles in several tumors. However, the clinical application value of HOTAIR in digestive system malignancies remains to be clarified. We aimed to explore comprehensively the potential role of HOTAIR as a prognostic indicator in digestive system malignancies.
  
  
  METHODS
  Systematic search was performed in Pubmed, Embase, Cochrane Library, and Web of Science until July 5, 2014. A quantitative meta-analysis was conducted with standard statistical methods for eligible papers on the prognostic value of HOTAIR in digestive system cancers.
  
  
  RESULTS
  A total of 1059 patients from 13 studies were included in the meta-analysis. A significant association was found between HOTAIR abundance and poor overall survival (OS) of patients with digestive system malignancies, with pooled hazard ratio (HR) of 2.587 (95% confidence interval [CI]: 2.054-3.259, P < 0.001). By combining HRs from Cox multivariate analyses, we found HOTAIR was an independent prognostic factor for OS without obvious heterogeneity (HR: 2.405, 95% CI: 1.883-3.0722, P < 0.001). Subgroup analysis showed that tumor type, histology type, region, publication year, sample size, and quality score did not alter the predictive value of HOTAIR as an independent factor for survival. Meta-regression and sensitivity analysis both suggested the reliability of our findings. A slight publication bias was observed. After adjustment by nonparametric "trim-and-fill" method, the corrected HRs had no significant change.
  
  
  CONCLUSIONS
  HOTAIR could be exploited as a novel prognostic biomarker for patients with digestive system malignancies.
authors.affiliation: Department of Thoracic Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Thoracic Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wang
mesh_terms: D015415:Biomarkers / Q000032:analysis; D016206:Databases, Bibliographic; D004067:Digestive System Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000401:mortality; D005260:Female; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D062085:RNA, Long Noncoding / Q000032:analysis*; D015203:Reproducibility of Results; D015996:Survival Rate
chemical_list: D015415:Biomarkers; C561566:HOTAIR long untranslated RNA, human; D062085:RNA, Long Noncoding
keywords: HOTAIR; cancer; digestive system; lncRNA; prognosis