LncRNA NORAD as a Novel Predictor of Lymph Node Metastasis and Prognosis in Solid Tumors: A Systematic Review and Meta-Analysis

Abstract

Background: Non-coding RNA-activated by DNA damage (NORAD), a novel identified lncRNA, was found to be aberrantly expressed in various types of cancer. This meta-analysis was performed to evaluate the value of lncRNA NORAD as a prognostic biomarker in human cancers. Methods: We searched PubMed, Web of Science, PMC, and Embase databases thoroughly for eligible literatures. Studies which explored the relationship of lncRNA NORAD expression with clinical outcomes in human cancers were included in our meta-analysis. Review Manager version 5.3 and Stata SE 12.0 were used to perform the data analyses. Results: Our meta-analysis results indicated that cancer patients with high lncRNA NORAD expression tended to have unfavorable overall survival (OS) (HR = 1.67; 95% CI, 1.44-1.95; P < 0.00001). Moreover, elevated lncRNA NORAD expression showed a significant relationship with poor tumor grade (OR = 1.61; 95% CI, 1.01-2.56; P = 0.05) and more lymph node metastasis (LNM) (OR = 2.66; 95% CI, 1.60-4.43; P = 0.0002). Conclusions: LncRNA NORAD could serve as a valuable biomarker to predict poor prognosis and LNM in various human tumors.