Prognosis Value of Low microRNA-34a Expression in Human Gastrointestinal Cancer: A Meta-Analysis

Abstract

Background: Mounting evidence shows that microRNA-34a (miR-34a) is involved in cancer prognosis. Therefore, we summarize the predictive role of miR-34a for survival in patients with gastrointestinal cancers (GICs). Methods: All the eligible studies were searched by PubMed, Web of Science and EMBASE and survival results were extracted. Then, the hazard ratio (HR) with corresponding 95% confidence intervals (CIs) was calculated to evaluate the prognostic role of miR-34a in GICs. The association between miR-34a expression and clinicopathological characteristics was estimated by odds ratio (OR) and 95%CIs. Results: A total of 20 studies were included in this meta-analysis. For overall survival (OS), the lower miR-34a expression significantly predicted poorer outcome in GICs, with the pooled HR of 1.86 (95% CI: 1.52-2.28, P<0.01). For disease-free survival (DFS), progressive-free survival (PFS), and recurrence-free survival (RFS), the lower miR-34a expression revealed worse DFS/PFS/RFS with the pooled HR of 1.86 (95% CI: 1.31–2.63, P < 0.01). Significant relation of differentiation/TMN stage/lymphatic metastasis and the expression level of miR-34a was identified. Conclusion: This meta-analysis reveals that lower miR-34a expression is significantly connected with worse OS and DFS/PFS/RFS of GICs patients. In addition, miR-34a expression level is relatively lower in patients with lymph node metastasis than patients without, and decreased miR-34a expression level is linked to poor tumor differentiation and late TMN stage. MiR-34a may become a new factor for prognosis prediction and progression of GICs.