Path-43. Targeted Genomic Analysis of Primary Adult Brain Tumors: A Single Institutional Experience of 26 Cases

Abstract

BACKGROUND In the United States, primary brain tumors comprise 2% of all cancers with an alarming 5-year survival rate of 35% [1,2]. To aid histopathological diagnosis, genomic profiling of tumors using next generation sequencing (NGS) has allowed more accurate molecular subclassification of tumors and identification of novel, subtype specific therapies in management [3]. We present single institutional data of molecular gene profiles in patients with adult primary brain tumors. Understanding the genetic landscape of these tumors will help determine molecular targets for currently available drugs and open new avenues for further drug development [4]. METHODS We retrospectively reviewed all primary brain tumor patients seen at LSU Health Science Center Shreveport who underwent NGS from July, 2017 to July, 2019. After reviewing a total of 44 patient charts, 26 were identified to have all the data required for our analysis. Standardized genetic sequencing reports made by molecular pathologists were used. Genetic mapping was performed and descriptive analysis was done using Statistical Analysis System (SAS). RESULTS Demographic characteristics of our patients consist of 50% males, 15% African American with an average age of diagnosis 59. The histopathological types diagnosed include 65% glioblastoma-multiforme and others comprising of gliosarcoma, pilocytic astrocytoma, ganglioma, oligodendroglioma, anaplastic oligodendroglioma, anaplastic ganglioma, meningioma, hemangiopericytoma, and astroblastoma. In 23% of patients, the results of gene sequencing in addition to histopathology impacted the clinical management by improving subclassification and in identifying targetable mutations. 42% of our patients found to have targetable mutations. CONCLUSION In the era of precision oncology, targeted gene sequencing of adult primary brain tumors may aid in diagnosis beyond histopathology by identifying the genetic landscape of tumors and molecular targets for individualized therapies.