SDPS-35 TUMOR-RELATED EPILEPSY IN HIGH-GRADE GLIOMA: A LARGE SERIES SURVIVAL ANALYSIS

BACKGROUND: Seizures are a common clinical occurrence throughout the disease course in glioblastoma (GBM). While many studies have explored the impact of surgical and medical treatment for GBM on seizure incidence and prevalence, limited study has been directed towards the prognostic effect of seizures occurring in the post-treatment setting. METHODS: We retrospectively reviewed 238 patients with histologically-confirmed high grade glioma treated at our institution between 2018 and 2021. Seizure presentation was classified as early onset (occurring at the time of GBM presentation), or late onset (first seizure occurring after beginning standard surgical and medical treatment). Using a multivariate Cox proportional-hazards model, hazard ratios were assessed for timing of seizure presentation, as well as other clinical and tumor-associated variables. RESULTS: Incidence of first seizure after the onset of treatment was found to be associated with improved overall survival (HR=0.66, p=0.03), while increasing age (HR 1.02, p=0.007) and deep/midline tumor location (HR 1.86, p=0.003) were associated with decreased overall survival. CONCLUSION: While seizure at presentation may be associated with better survival in high-grade glioma, more analysis is underway to confirm the finding in a larger cohort and to evaluate the impact of molecular alterations in seizure incidence and management. Further study in this patient cohort utilizing detailed next-generation sequencing will evaluate the association of the patient-specific tumor profile on seizures and overall survival.