Diagnostic Potential of Circulating miRNAs in Glioma: A Systematic Review and Meta-Analysis

Gliomas are intracranial tumors characterized by limited diagnostics and treatment approaches. Blood-circulating miRNAs represent a regulatory class of molecules that change their expression under pathological conditions and can relatively easily be detected. The present study evaluates the diagnostic potential of blood-circulating miRNAs in glioma. All grades of gliomas are included in the analysis. The articles were retrieved from the PubMed, Web of Science and Scopus databases up to October 2025. The studies were considered to be eligible if they used glioma patients and healthy controls and compared their miRNA levels, indicating sensitivity and specificity values. Risk of bias was assessed using the QUADAS-2 tool. The collected data was pooled by the STATA 19.0 MP bivariate random effects model and indicated heterogeneity using the I² statistic value. To identify possible reasons for heterogeneity, we utilized subgroup analysis and meta-regression. Publication bias was assessed with Deeks' funnel plot, and the test diagnostic potential was evaluated with Fagan's nomogram. We analyzed 31 original reports covering 2299 glioma patients and 1719 healthy controls. A meta-analysis on 59 data points extracted from the analyzed papers was conducted. The combined pooled sensitivity was found to be equal to 0.83 (95%CI: 0.80-0.86), the specificity 0.88 (95%CI: 0.85-0.90), the positive likelihood ratio 6.7 (95%CI: 5.4-8.5), the negative likelihood ratio 0.19 (95%CI: 0.16-0.23), and the diagnostic odds ratio 35 (95%CI: 25-50). An SROC analysis revealed an AUC equal to 0.92 (95%CI: 0.90-0.94). The reported diagnostic parameters imply that blood-circulating miRNAs hold the potential to be developed into diagnostic biomarkers for glioma identification. However, the high heterogeneity in the analyzed studies suggests that the results should be considered as exploratory only.