Clinical and molecular characterization of adult glioblastomas in Southern Brazil

Abstract

We investigated 113 adult Brazilian patients with glioblastoma (GBM) for comparison with patients from distinct geographical areas and evaluation of suitability for novel targeted therapies. Patients were assessed for clinical features and tumor genomic characteristics such as ROS1 and NTRK1 rearrangements, KIT, PDGFRA, and KDR amplification, and RB1 deletion using multicolor fluorescence in situ hybridization. The majority of patients were male (53%), over 40 years (94%), with tumor located in single site (64%), in the right cerebral hemisphere (60%), and underwent partial resection (71%); 14% presented complications after surgery. The main clinical sign at diagnosis was focal abnormality (57%); frontal (31%); and temporal (20%) regions were most commonly affected. Median hospitalization time was 20 days, median survival was 175 days. One tumor was positive for rearrangement in NTRK1 and another in ROS1 (0.9% each). PDGFRA was amplified in 20% of cases, often co-amplified with KDR (>90%) and KIT (>60%). RB1 was deleted in 16% of patients. There was no association between these molecular abnormalities and patient survival. However, older age, complications after surgery, and right-sided tumors were independent variables associated with patient survival. This study contributes information on the molecular profile of glioblastomas in Latin America possibly supporting new target therapies.