Potential Diagnostic Value Of Circulating Mir-30a-3p For Non-Small Cell Lung Cancers: Meta-Analysis From Microarray Datasets

Background and objective: Aberrant microRNAs (miRNAs) have been reported to play vital roles in the tumorigenesis and progression of non-small cell lung cancers (NSCLCs). Several circulating miRNAs have also been demonstrated as potential biomarkers in early diagnosis of NSCLCs. However, the clinical diagnostic value of circulating microRNA-30a-3p (miR-30a-3p) of NSCLCs has not been clarified. Thus, the current meta-analysis was carried out to assess the possibility of circulating miR-30a-3p as a biomarker with microarray datasets for early detection of NSCLCs. Material and Methods: The NCBI Gene Expression Omnibus (GEO) database and EBI ArrayExpress database were searched to collect NSCLC-related miRNA microarray datasets for detection of circulating miRNA levels until 30th September, 2015. Limma package and ExiMiR package in R were used to evaluate the quality control of the data output. Standardized mean difference (SMD) together with 95% confidence intervals (CIs) of miR-30a-3p level from included datasets was pooled with STATA 12.0. Heterogeneity was evaluated by Cochran's Q test and the I-2 statistic. A p value<0.005 or I-2>50% was regarded as significant heterogeneity. Additionally, sensitivity analysis was performed to estimate the stability of the pooled results. Results: Six miRNA datasets (GSE61741, GSE46729, GSE40738, GSE24709, GSE17681 and GSE27486) from blood samples were selected, including 250 NSCLC patients and 242 healthy controls. A marginal alteration of circulating miR-30a-3p level was observed between NSCLC cases and control groups; however, the p value did not reach the statistically significant standard (SMD = 0.169; 95% CI, -0.012 to 0.350; P = 0.067). No significant heterogeneity was generated by random-effects model (P = 0.186, I-2 = 33.4%). Furthermore, sensitivity analysis showed stable results of the current meta-analysis. Conclusions: MiR-30a-3p expression levels in whole blood and peripheral blood cells show no significant differences between NSCLC patients and healthy controls; thus it might be ineffective to detect circulating miR-30a-3p expression for an early diagnosis of lung cancer. However, larger cohorts are required to verify this finding.