The prognostic value of long noncoding RNA MEG3 expression in the survival of patients with cancer: A meta-analysis.

Long noncoding RNAs (lncRNAs) play an important role in carcinogenesis and cancer progression. lncRNA maternally expressed gene 3 (MEG3) is a tumor suppressor that is downregulated in several cancers. However, its prognostic value in human malignancies remains controversial. We have therefore undertaken a meta-analysis to explore the relationship between cancer survival and the expression of lncRNA MEG3. A systematic literature search identified 13 potentially eligible investigations comprising 1733 patients in nine different cancer types. In the pooled analysis, a low expression of MEG3 was associated with low overall survival (OS) in patients with cancer having a combined hazard ratio (HR) of 0.830 (HR = 0.83; 95% CI: 0.70-0.98; p = 0.03; random effect model). However, subgroup analysis according to cancer type revealed that MEG3 expression was not associated with better OS in gastrointestinal cancer (HR = 0.58, 95% CI = 0.33-1.03; p = 0.06), and patients with breast cancer (HR = 0.85, 95% CI: 0.12-5.88; p = 0.87). In conclusion, our results demonstrate that only in the pooled analysis, there was a significant relationship between MEG3 expression and cancer survival. Further investigation of other molecular biomarkers involved in tumorigenesis-related pathways is necessary.