The Impact of Extensive Surgical Resection of Butterfly Glioblastomas on Outcomes in the Presence of TERT Mutation and EGFR Amplification: A Retrospective Cohort Study.

Abstract

Background and objectives: This study aimed to assess if extensive surgical resection enhances outcomes in wild-type Isocitrate Dehydrogenase (IDH) butterfly glioblastoma (B-GBM) patients, despite the presence of Telomerase Reverse Transcriptase (TERT) mutation and Epidermal Growth Factor Receptor (EGFR) amplification.

Methods: The study, retrospectively conducted from 2014 to 2022, involved 723 GBM patients, 41 of whom met the criteria for IDH wild-type B-GBM. Exclusion criteria comprised prior diagnoses or treatments for low-grade glial tumors. Surgeons, employing two approaches-partial and extensive surgery-categorized patients based on age, sex, tumor location, corpus callosum involvement, and genetic characteristics. The interval between initial surgery and tumor recurrence/tumor-free period (TR/TFP) and overall survival (OS) were recorded and compared between the partial and extensive resection groups, analyzing the impact of resection width on TR/TFP and OS. Preoperative assessments utilized thin-section cranial computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI). Intraoperatively, tumor excision was guided by sodium fluorescein, and margins were delineated via neuronavigation. Genetic alterations (TERT mutations and EGFR amplifications) were correlated with surgical type, TR/TFP, and OS. Karnofsky Performance Scale (KPS) evaluations were performed pre- and post-operatively and at key intervals, comparing outcomes between surgical groups. Standard radiotherapy and chemotherapy regimens were administered to all patients.

Results: Extensive resection yielded significantly longer TR/TFP compared to partial resection, despite TERT gene mutation and EGFR amplification being linked to shorter TR/TFP and OS. Its impact on OS, however, was not significant. KPS scores indicated a superior quality of life after extensive resection, with sustained improvement upon recurrence.

Conclusions: Extensive resection of B-GBM, even in the presence of adverse genetic alterations, may prolong TR/TFP, offering patients a period of improved comfort with minimal distress.