Association Between miRNAs and the Diagnosis, Prognosis, and Recurrence of Patients with Meningioma: A Systematic Review.

To evaluate the diagnostic, prognostic, and recurrence-related roles of microRNAs (miRNAs) in meningioma based on expression profiles across different biological samples. This systematic review was conducted in accordance with Cochrane Collaboration and PRISMA guidelines. A search was performed in PubMed, Scopus, Web of Science, and Google Scholar without language restrictions. Cohort and case–control studies assessing miRNA expression in tumor tissue, serum, or cerebrospinal fluid from patients with histologically confirmed meningioma were included. Risk of bias was evaluated using the Newcastle–Ottawa Scale. Bioinformatic pathway enrichment analyses were conducted for recurrently miRNAs. Twenty-three studies involving 1615 participants were included, of whom 1461 had meningiomas (WHO grades 1–3). Overall, 153 miRNAs were evaluated, including 90 upregulated, 45 downregulated, and 18 without significant differential expression. miR-21, miR-34a, and members of the miR-181 family were consistently associated with tumor grade and progression. Tumor recurrence was most frequently linked to miR-224-5p, miR-331-5p, miR-29c-3p, and miR-219-5p. Circulating miRNAs, particularly miR-497 and miR-219, demonstrated diagnostic potential in serum and cerebrospinal fluid. Pathway analyses highlighted enrichment in metabolic and signaling pathways, including sphingolipid, sulfur, and fatty acid metabolism. This review identifies miR-21, miR-224-5p, miR-331-5p, miR-29c-3p, and circulating miR-497 and miR-219 as the most promising miRNA biomarkers for meningioma diagnosis, grading, and recurrence monitoring. Despite methodological heterogeneity, the consistency of these findings across independent studies supports their translational potential. Nonetheless, large, standardized studies with independent validation cohorts are required prior to clinical implementation.