MicroRNAs as noninvasive biomarkers in bladder cancer detection: a diagnostic meta-analysis based on qRT-PCR data

As the diagnostic significance of microRNAs (miRNAs) in the detection of bladder cancer is controversial, we aimed to perform a meta-analysis to comprehensively assess the diagnostic value of miRNAs in blood and urine for detecting bladder cancer.

A systematic literature search of public databases was conducted to obtain qualified studies. Sensitivity was utilized to plot the summary receiver operator characteristic (SROC) curve against specificity and the area under the SROC curve (AUC) was generated to evaluate the pooled diagnostic efficiency. Subgroup analyses and meta-regression were applied to investigate the underlying sources of heterogeneity. The STATA 12.0 software was used to perform all statistic analyses.

A total of 58 studies from 22 articles comprising 4,558 bladder cancer patients and 4,456 controls were included in our meta-analysis. MiRNAs in blood and urine manifested relatively good diagnostic efficiency in detecting bladder cancer, with a sensitivity of 0.74, a specificity of 0.78, and an AUC of 0.83. Multiple-miRNA assays were more accurate than single-miRNA ones in bladder cancer diagnosis. Blood-based miRNA assays displayed better diagnostic performance than urine-based ones. In addition, miRNAs showed reduced diagnostic value in bladder cancer among Caucasians compared with Asians.

MiRNAs in blood and urine, especially the combination of multiple miRNAs, may serve as hopeful noninvasive biomarkers for early diagnosis of bladder cancer. Further extensive prospective research is needed to verify their clinical significance in bladder cancer diagnosis.