P21.04.A IMPROVEMENTS IN SURVIVAL FOR GLIOBLASTOMA IN THE POST-STUPP PROTOCOL ERA

Abstract BACKGROUND The Stupp protocol was accepted as standard of care for glioblastoma in 2005, and has led to significant increases in overall survival. Prior analyses have identified additional survival gains post-Stupp, though the source of these is unknown. In this analysis, we leveraged two large datasets to identify trends in survival and potential treatment factors associated with these improvements. MATERIAL AND METHODS Provider-side commercial claims data were obtained from IQVIA for adults (18+ years) diagnosed with malignant brain tumor (ICD-9/ICD-10:191.0-191.9/C71.0-C71.9) from 2015-2021 who received biopsy/resection and temozolomide within 60 days of diagnosis. Treatment patterns were determined using ICD-9/ICD-10 procedure and HCPCS/CPT codes. Death was determined by CPT codes or last claim followed by ≥30 days of no claims. Elixhauser comorbidity score was generated prior to diagnosis. Population-based survival data were obtained from the National Program of Cancer Registries (NPCR) from 2004-2018 for microscopically-confirmed adult (18+ years) glioblastoma cases receiving surgery and radiation. Median survival was estimated using Kaplan-Meier regression, and cox proportional hazards models were used to assess potential prognostic factors. Survival analyses were censored at 36 months. RESULTS The IQVIA dataset had 18,883 individuals and NPCR had 92,540 individuals identified as being diagnosed with glioblastoma and meeting treatment criteria. Median survival among IQVIA cases was 13.9 months (95%CI=13.7-14.1), and 14 months (95%CI=14-14) in NPCR. Median survival in NPCR increased from 11 months in 2004-2006, to 14 months in 2016-2018. Within IQVIA, 19% of individuals had ≥1 claim for Bevacizumab and 15.5% had ≥1 claim for tumor treating fields (TTFields). Use of TTFields and/or Bevacizumab in treatment were associated with significantly improved survival after adjustment for age, sex, and comorbidities. CONCLUSION s: Survival in glioblastoma continues to improve over time, which may be due to developments in therapeutic approaches. Assessment of population-level survival patterns is essential for understanding the impact of treatment advancements.