Prognostic significance of microRNA-200c in various types of cancer: An updated meta-analysis of 34 studies

Abstract

Previous studies have indicated that miR-200c is a promising cancer biomarker. However, different studies have presented conflicting results. Therefore, the aim of the present study was to perform a meta-analysis of miR-200c based on 34 relevant studies. The Materials and methods sections of papers were carefully identified using the databases PubMed, Web of Science and Embase for publications up to December 4, 2015. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were systematically calculated to investigate the association between the expression of miR-200c and cancer prognosis. The results demonstrated that elevated expression levels of miR-200c indicated significantly worse overall survival rates (HR=1.37, 95% CI: 1.01, 1.85), and a high level of miR-200c was considered an indicator of an unfavorable prognosis in patients from Europe and America (HR=1.85, 95% CI: 1.27, 2.69). Furthermore, overexpression of miR-200c was significantly associated with progression of the disease in the subgroups of tissue and blood samples (HR=0.68 and 2.45, respectively), and inferior overall survival rates for the blood subgroup were revealed (HR=2.21, 95% CI: 1.04, 4.72). In addition, miR-200c was of prognostic value in several disease subgroups. Taken together, high expression levels of miR-200c are of significant prognostic value in various human malignancies.

Keywords: cancer; hazard ratio; meta-analysis; miR-200c; prognosis.

Figure 1.

Flow diagram with details of the study selection process.

Figure 2.

Forest plots of the combined analyses of the association of CSS/OS and expression levels of miR-200c. (A) Forest plots of the pooled analysis of CSS/OS. Squares and horizontal lines correspond to study-specific HRs and 95% CIs, respectively. The area of the squares correlates with the weight, and the diamonds represent the pooled HRs and 95% CIs. (B) Forest plots of the pooled analysis of CSS/OS in different disease type subgroups. (C) Forest plots of the pooled analysis of CSS/OS in blood sample subgroup. CSS, cancer-specific survival; OS, overall survival; HR, hazard ratio; CI, confidence interval.

Figure 3.

Forest plots. (A) Forest plots of the pooled analysis of the association of RFS/PFS/DFS and miR-200c expression in different sample subgroups. (B) Forest plots of the pooled analysis of RFS/PFS/DFS in the in the non-small cell lung cancer subgroup. RFS, recurrence-free survival; PFS, progression-free survival; DFS, disease-free survival; HR, hazard ratio; CI, confidence interval.

Figure 4.

Sensitivity analyses and Begg's funnel plots. (A) Sensitivity analysis of the effect of individual studies on the CSS/OS results. (B) Sensitivity analysis of the effect of individual studies on the RFS/PFS/DFS results. (C) Begg's funnel plots to test for the publication bias in the overall analysis of CSS/OS. Each point represents a separate study. (D) Begg's funnel plots to test for publication bias in the overall analysis of RFS/PFS/DFS. RFS, recurrence-free survival; PFS, progression-free survival; DFS, disease-free survival; HR, hazard ratio; CI, confidence interval.