SURG-23. THE INFLUENCE OF PRE-OPERATIVE VARIABLES ON SURVIVAL OF PATIENTS WITH GLIOBLASTOMA

Abstract

Abstract BACKGROUND Glioblastoma (GBM) is both the most common and most aggressive brain tumor in adults. Despite treatment advances, prognosis remains poor and is influenced by numerous factors. METHODS Patients treated at our institution for glioblastoma were reviewed to identify pre-treatment factors that could increase survival time. 183 treated for high-grade GBM between 2017 and 2021 with complete follow-up data were included. Overall (OS) and progression-free survival (PFS) were calculated with Kaplan-Meier analysis. Cox regression analysis identified the influence of several pre-treatment factors (age, Karnofsky performance status (KPS), radiographic distribution of tumor, and MGMT methylation status) on survival time. RESULTS Average age was 64.9 years. At presentation, 69.9% of patients had KPS > 80. Multifocal tumors occurred in 24.6% of patients, involving an average of 2 distinct regions (either multifocal or unifocal lesions). MGMT methylation was confirmed in 17.5% of patients. Recurrence occurred in 46.4% of patients. Median OS was 21.6 (14.3 – 28.9) months and PFS was 13.4 (10.6 – 16.1) months. MGMT methylation was associated with significantly longer median OS (36.9 vs. 17.0 months, p = 0.012) and PFS (20.0 vs. 10.3 months, p = 0.002) compared to those without. Cox regression confirmed MGMT methylation to be significantly associated with longer PFS (HR -0.883, p = 0.004) and OS (HR -0.785, p = 0.014). Age (HR 0.03, p = 0.003) and KPS > 80 (HR -0.7, p = 0.006) significantly impacted OS, but not PFS. Tumor extent did not impact survival. CONCLUSIONS We found that multifocal tumor, greater number of involved regions. and older age were associated with shorter OS, while MGMT methylation was associated with longer OS. Similar correlations were found for PFS. In upcoming trials, these factors may need to be controlled for between groups in order to accurately determine the effect of new treatments.