Diagnostic acuuracy of cerebrospinal fluid and serum-isolated exosomes for glioblastoma: a systematic review and meta-analysis

Glioblastoma (GBM) is the most malignant glioma cancer with a high morbidity and mortality worldwide. Unfortunately, a routine method is not available for screening or preoperative early detection of GBM. However, early detection in a none-invasive or minimally invasive method could be beneficial and increase the survival rate. In this systematic review and meta-analysis, we aimed to examine the diagnostic accuracy of exosomal RNAs that were extracted from patients’ CSF or serum for GBM diagnosis. We searched Web of Science, Scopus, PubMed (including Medline), Embase and ProQuest (as databases for grey literature) up to December 2019; we also performed backward and forward reference checking of included and relevant studies. Finally, included studies were assessed with QUADAS-2 checklist and their data extracted. We carried out a meta-analysis of included study, regarding to the diagnostic meta-analysis guidelines for obtaining pooled accuracy estimates. In addition, sensitivity analysis and meta-regression were also conducted. We retrived 1730 records from databases, nine of them included in systematic review and qualitative synthesis. Six studies were considered to statistical analysis and performed diagnostic meta-analysis. Our results suggested that the pooled sensitivity and specificity of exosomal biomarkers for GBM were 0.76 and 0.80, respectively. In addition, the pooled positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were 3.7, 0.30 and 12, respectively. The overall area under the curve (AUC) of exosomal biomarkers for GBM diagnosis was found to be 0.85. According to our results, the value of 0.85 for AUC, suggesting that exosomal biomarkers might serve as a high potential and non-invasive diagnostic tool for GBM.