Impact of next generation sequencing in high grade glioma management.

Abstract

e14031Background: Recent advances in genomic profiling have improved our understanding of the molecular pathogenesis of high grade gliomas. Increased availability of high-throughput Next Generation Sequencing (NGS) allows the identification of genetic alterations which could direct personalized cancer treatments for HGG patients. Methods: All patients with high grade glioma (WHO Grade ≥3 glioma by 2016 or 2022 classification) in our institution, who underwent NGS testing between 2019-2023, were identified from a prospectively maintained electronic database. NGS results, from the Oncomine Precision Assay, a multi-gene panel which tests for 50 different mutations, were collated. Medical records were systematically reviewed to collect demographic, treatment and survival data. Alterations detected on NGS were characterized using the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT). Results: 53 patient samples underwent NGS testing (34 males [64%]; 19 females [36%]). Median age at diagnosis was 52 years (range: 20-72 years). Thirty patients (57%) had an ECOG PS 1 at first clinical review. 18 tumors (34%) were found to have MGMT promoter hypermethylation. 28 patients (53%) were found to have potentially actionable alterations according to the ESCAT scale; 19 (35%) EGFR mutations (ESCAT IIIA level evidence) were detected, 5 PIK3CA (9%) mutations (ESCAT IIIA), 3 FGFR3 (6%) alterations (ESCAT IIB), 2 patients with CDK 4 (4%) copy number gain (ESCAT IIIA), 2 PTPRZ1-MET (4%) fusions (ESCAT IIIA) and 1 BRAF V600E (2%) mutation (ESCAT IB). 4 patients were found to have multiple mutations on NGS. 1 sample had insufficient tissue for analysis. 2 patients (4%) were considered for targeted therapy based on NGS results (1 BRAF V600E mutation and 1 FGFR3 alteration) but both deteriorated in advance of commencing treatment. One patient received nivolumab for MSI-H recurrent GBM (ESCAT IIIB) but progressed within 3 months of commencing treatment. Conclusions: Despite advances in our understanding of the pathogenesis of these high grade gliomas and improved awareness of molecular targets, the delivery of targeted therapy to patients with HGG remains challenging. Rapid access to targeted therapy via compassionate access programmes and improved availability and access to clinical trials for patients with rare cancers and molecular alterations, is paramount.