A Meta-Analysis of the Prognostic Value of Abnormally Expressed lncRNAs and Correlation with Clinicopathological Characteristics in Glioma

Objectives: Abnormal expression of lncRNAs are involved in the occurrence and development of glioma. Thus, we conducted a meta-analysis to clarify the prognostic value of lncRNAs in glioma integrally. Methods: Pubmed, Web of Science, Embase, Cochrane Library, Clinical Trial.gov and Trip database were searched. Hazard ratio (HR) and 95% confidence intervals (CI) were calculated in the analysis of prognostic indicators. Odds ratio (OR) and 95%CI were applied to estimate the association between lncRNAs and clinicopathological features. Results: The expression level of lncRNA was significantly correlated with the OS rate of glioma patients (HR=1.29, 95%CI: 1.03-1.61, p=0.03). The low expression of CASC2 (HR=0.42, 95%CI: 0.27-0.66, p=0.0001) showed a poor prognosis of glioma patients. MALAT1 (HR=1.42, 95%CI: 0.38-5.29, p=0.60), HOTAIR (HR=1.70, 95%CI: 0.69-4.21, p=0.25) and TUSC7 (HR=1.81, 95%CI: 0.87-3.75, p=0.11) have no statistical significance for the prognosis of glioma patients. The high expression of lncRNA was related to WHO staging (OR=0.31, 95%CI: 0.19-0.50, p<0.00001), EGFR expression (OR=3.14, 95%CI: 1.70-5.77, p=0.0002) and IDH1 status (OR=0.33, 95% CI: 0.12-0.93, p=0.04), while unrelated to age (OR=1.05, 95%CI: 0.78-1.42, p=0.75), gender (OR=1.01, 95%CI: 0.85-1.20, p=0.92), tumor size (OR=0.67, 95%CI: 0.35-1.27, p=0.22), PTEN (OR=0.26, 95%CI: 0.06-1.10, p=0.07), KPS score (OR=1.06, 95%CI: 0.44-2.59, p=0.90), MGMT promoter methylation (OR=2.05, 95%CI: 0.94-4.50, p=0.07) and the recurrence (OR=0.87, 95%CI: 0.42-1.82, p=0.72). Conclusion: Abnormal expression of lncRNAs were related to survival of glioma patients and may serve as potential prognostic indicators in glioma. The higher expression level of lncRNAs, the worse prognosis of glioma. The expression of lncRNA CASC2 is correlated with the prognosis of glioma patients. The higher the expression level of CASC2, the better prognosis. LncRNAs are related to WHO staging, EGFR expression and IDH1 mutation, while unrelated to age, gender, tumor size, PTEN, KPS score, MGMT gene promoter methylation or tumor recurrence.