Blood derived extracellular vesicles in patients with glioblastoma: preliminary experience from a monoinstitutional series

Purpose: Glioblastoma (GB) is the most common and aggressive primary brain tumor in adults, with its significant inter- and intra-tumoral heterogeneity being a major factor in its treatment resistance and overall prognosis. GB diagnosis typically involves magnetic resonance imaging, confirmed by histology after surgical resection or biopsy. Recurrence is almost expected despite adjuvant therapies. Extracellular vesicles (EVs) may represent promising cancer biomarkers for diagnosis, prognosis, and therapeutic monitoring. Methods: In this work, we monitored 21 GB patients at different time intervals performing a quantitative and dimensional analysis of plasma-derived EVs, with the aim of finding correlations with their clinical course. Results: Our analyses revealed a slight correlation with patients’ clinical conditions during follow-up, such as tumor time recurrence over time, but no significant difference in plasma EV concentration in GB patients and healthy control subjects (HC), contrary to previously published data. Conclusions: Although based on a limited number of patients, our methodological study highlights the need for a universal analysis method to compare data from large patient populations in order to use EVs as a biomarker for the diagnosis of recurrence by liquid biopsy, especially in GB, a tumor known for its heterogeneity.