Circulating Tumor Cells in Glioblastoma

Glioblastoma multiforme (GBM) remains a devastating brain tumor with poor prognosis, traditionally viewed as non-metastatic. The recent detection of circulating tumor cells (CTCs) in glioblastoma challenges this view, which opens up novel opportunities for liquid biopsy in neuro-oncology. This review summarizes current understanding of glioblastoma CTCs, emphasizing their unique properties, detection technologies, and differences compared to CTCs in extracranial cancers. Their rarity, their lack of epithelial markers, and the blood-brain barrier hinder the detection of glioblastoma CTCs, necessitating specialized enrichment approaches. Despite these challenges, CTC analysis can offer helpful information regarding tumor heterogeneity, treatment response, and minimal residual disease. We discuss emerging clinical studies leveraging CTCs for early relapse detection and therapy monitoring. The integration of CTC phenotype, molecular profiling, and functional characterization has clear potential for enhancing personalized treatment strategies in glioblastoma. Refined CTC methodologies combined with other liquid biopsy modalities may transform glioblastoma management, improving patient outcomes through less invasive, dynamic tumor surveillance.