Purpose of review: Liquid biopsy is a sampling of tumor cells or tumor nucleotides from biofluids. This review explores the roles of liquid biopsy for evaluation and management of patients with primary and metastatic CNS malignancies.
Recent findings: Circulating tumor cell (CTC) detection has emerged as a relatively sensitive and specific tool for diagnosing leptomeningeal metastases. Circulating tumor DNA (ctDNA) detection can effectively demonstrate genetic markup of CNS tumors in the cerebrospinal fluid, though its role in managing CNS malignancies is less well-defined. The value of micro RNA (miRNA) detection in CNS malignancies is unclear at this time. Current standard clinical tools for the diagnosis and monitoring of CNS malignancies have limitations, and liquid biopsy may help address clinical practice and knowledge gaps. Liquid biopsy offers exciting potential for the diagnosis, prognosis, and treatment of CNS malignancies, but each modality needs to be studied in large prospective trials to better define their use.
Keywords: Brain metastases; Brain tumor; CNS; CSF; CTC; Central nervous system; Cerebrospinal fluid; Circulating tumor DNA; Circulating tumor cells; Liquid biopsy; RNA; cfDNA; ctDNA; miRNA.