Association of Health Disparities with Glioblastoma Treatment and Outcomes: Insights from a 15-Year National Cohort (2005–2020) ^†

Background: Despite advances in glioblastoma (GBM) management, median overall survival (mOS) remains poor, and multi-modal disparities persist. We sought to evaluate trends in GBM treatment and survival outcomes from 2005–2020, with a focus on sociodemographic and geographic disparities. Methods: We conducted a retrospective US-based cohort study using the National Cancer Database (NCDB), stratifying study period into four intervals (2005–2008, 2009–2012, 2013–2016, and 2017–2020). Logistic regression was used to identified predictors of receipt of combination surgery, radiation, and chemotherapy (Sx+RT+Chemo). Kaplan–Meier and multivariable Cox proportional hazards approaches were used to assess mOS. Results: A total of 111,955 adults with GBM were included. From 2005–2008 to 2017–2020, mOS increased from 7.8 to 9.5 months, with geographically unequal gains in survival across the US. In multivariable logistic regression model adjusting for known confounders, combined Sx+RT+Chemo was less likely to be received by female patients (OR 0.90, 95%CI 0.88–0.92) vs. male, non-White patients (OR 0.90, 95%CI 0.86–0.94) vs. White, patients treated at community hospitals (OR: 0.78, 95%CI 0.76–0.80) vs. academic centers, publicly-insured patients (OR 0.74, 95%CI 0.71–0.76) or uninsured patients (OR 0.54, 95%CI 0.50–0.58) vs. privately-insured, and patients living in the South (OR 0.88, 95%CI 0.85–0.91), Midwest (OR 0.83, 95% CI 0.80–0.86), and West (OR 0.85, 95%CI 0.81–0.88) compared to the Northeast. In multivariable Cox regression, significantly poorer survival was seen amongst non-metropolitan patients, community-based hospital patients, and publicly-insured and uninsured patients (vs. privately-insured), despite adjusting for prognostic factors. Conclusions: Only modest improvement in mOS of GBM patients has occurred across 2005–2020, with persistent disparities linked to sociodemographic and structural factors, whose redressal warrants multi-pronged efforts.