Unveiling the impact of corticosteroid therapy on liquid biopsy-detected cell-free DNA levels in meningioma and glioblastoma patients.

The liquid biopsy era has brought several possibilities to improve precision in patient care. Among the different sources of analytes, the cfDNA has been explored as a possible disease indicator, especially in cancer. Intracranial tumors still represent a challenge for liquid biopsy due to the blood-brain barrier being able to restrain both the migrating tumor cells and the liberation of cfDNA into the blood circulation. The aim of this work was to compare the differences between the cfDNA concentration in the plasma from patients with central nervous system tumors, and for this we analyzed a cohort of 188 individuals with glioblastoma (N = 57), brain metastasis (N = 15), meningioma (N = 90) and schwannoma (N = 26). Plasma samples were obtained immediately before tumor excision, and the cfDNA was isolated from the samples and quantified. The results showed that cfDNA plasma levels vary according to the tumors analyzed, with glioblastoma and brain metastasis presenting higher median levels of cfDNA than meningiomas and schwannomas. In addition, corticosteroid treatment resulted in higher cfDNA levels in meningioma and glioblastoma patients and vasogenic brain edema resulted in higher cfDNA levels only in meningioma patients. We hypothesize that cfDNA evaluation might have clinical monitoring value and that other clinical variables, such as corticosteroid used, should be considered during the liquid biopsy clinical evaluation of intracranial tumors.