RADT-38. CLINICAL, MOLECULAR AND IMAGING FEATURES ASSOCIATED WITH LONG TERM SURVIVAL IN GLIOBLASTOMA PATIENTS

Abstract INTRODUCTION Glioblastoma (GBM) is the most common malignant brain tumor in adults and has poor prognosis despite standard of care treatment. Nevertheless, certain patients surpass survival expectations. This study seeks to identify the clinical, molecular, and imaging characteristics of GBM associated with extended patient survival. METHODS In this retrospective cohort study, we examined records of adult GBM patients (WHO 2016 classification) treated at Thomas Jefferson University Hospital from 2010 to 2023. Exclusion criteria included a preoperative Karnofsky Performance Status (KPS) below 60 and treatment with hypo-fractionated radiation therapy. Patients were categorized into two groups: short-term survivors (STS), who survived less than 36 months from diagnosis, and long-term survivors (LTS), who survived more than 36 months. We reviewed patient charts and pathology reports for comprehensive clinical and molecular data. For radiomics analysis, tumor segmentation was performed using CaPTk software on the initial diagnostic MRI (T1 pre and post-contrast, FLAIR and T2 sequences). The relationship between overall survival of more than three years was analyzed with univariable logistic models for potential predictors using R statistical software. RESULTS Of the cohort of 210 patients, 37 (17.6%) survived beyond three years. The median age at diagnosis was 55 years (range; 29-79) Twenty-two patients were male and 15 were female. Twenty-two percent had IDH mutation and 65% had MGMT methylation. Factors associated with long-term survival included younger age at diagnosis (p =0.007), MGMT hypermethylation (p =0.019), IDH mutation (p=0.001), absence of TERT mutation (p = 0.002), higher average number of adjuvant temozolomide cycles (10 vs. 5; p = 0.005), and smaller volume of enhancing tumor on T1 post-contrast imaging segmentation (p=0.022). But there was no significant difference in FLAIR abnormality or necrotic core volumes between the groups. CONCLUSION In our cohort of GBM patients, patients diagnosed at a younger age, MGMT hypermethylation, IDH mutation, absence of TERT mutation, receiving more cycles of adjuvant temozolomide treatment, and smaller enhancing tumor volume on preoperative T1 post-contrast imaging were associated with longer survival. Future research involving larger cohorts and validation of our findings is needed.