Realização de biópsia Líquida para extração de DNA tumoral no líquido cefalorraquidiano (LCR) em pacientes com tumor cerebral

Abstract

Introduction: Gliomas are the most common primary tumors of the Central Nervous System (CNS), with glioblastoma multiforme (GBM) being the most malignant and aggressive form. Despite treatment, the overall survival of these patients varies from 15 to 23 months. Recent advances in the molecular characterization of gliomas have allowed the use of these characteristics to predict prognoses, guide individualized treatments and refine the classification of tumors. Liquid biopsy, which detects circulating tumor DNA (ctDNA) in CSF, has shown promise for early diagnosis of relapses, identification of tumor mutations and distinction between changes caused by radiotherapy and disease progression. In Brazil, there are no records of previous attempts to extract ctDNA from the CSF in patients with gliomas, representing a significant gap in the molecular management of these tumors. Materials and Methods: This is a prospective case series of patients with clinical and imaging findings of high-grade glioma. The patients underwent collection of biological material, including CSF, and two low-cost techniques were used to obtain ctDNA. For survival analysis, the Kaplan-Meier curve was used. Results: This prospective study included 16 patients with brain tumors, of which 13 were diagnosed with gliomas. The mean age of the patients was 52.1 ± 15.4 years, with a median KPS of 80%. Kaplan-Meier curve revealed high mortality among patients with gliomas, with only 46.2% survival at 5 months. The protocols used for ctDNA extraction were negative. Conclusion: This study highlights the first documented attempt in Brazil to extract ctDNA from CSF in patients with gliomas, highlighting the challenges inherent to this approach. Although the initial results were negative, the creation of a bank of biological material represents a valuable resource for continuing research, especially in a scenario where survival is extremely low when compared to developed countries.