Abstract 6632: Trends in treatment and survival among patients with glioblastoma in the United States, 2000 to 2020: A population-based SEER analysis.

Abstract Background: Population-level patterns in the real-world use of initial treatment combinations for glioblastoma remain poorly characterized. We evaluated national trends in treatment uptake over two decades and examined their associations with survival outcomes. Methods: We assessed temporal trends (2000-2020) in treatment and survival among 46,186 patients with glioblastoma in the SEER registry. Logistic regression modeled treatment utilization, and Cox regression estimated survival. Results: Among 46,186 patients (50.0% aged 40-65; 43.0% aged ≥65; 58.0% male), 43.5% underwent gross total resection (GTR), 32.0% subtotal resection, and 24.5% no surgery; 71.8% received radiotherapy and 61.3% received chemotherapy. From 2000 to 2020, utilization increased for any surgery (OR/year 1.03, 95% CI 1.028-1.036), radiotherapy (1.01, 1.010-1.017), and chemotherapy (1.08, 1.081-1.088), whereas the likelihood of GTR vs subtotal resection declined (0.92, 0.915-0.922). Triple therapy increased modestly (1.01, 1.005-1.012) but plateaued at 30%. Older age, non-lobar tumors, unmarried status, and lower income predicted lower odds of triple therapy; after adjustment, calendar year showed a marginal decline (aOR/year 0.99, 0.99-1.00). Median overall survival improved from 6.0 to 10.0 months, with gains in fixed-time survival. Conclusion: Standard triple therapy conferred the greatest survival benefit; however, GTR rates did not rise in recent years, and substantial disparities in receipt of standard care persisted. Efforts to expand equitable access and prioritize maximal safe resection are essential to achieve greater population-level survival gains. Citation Format: Jianan Chen, Qiong Wu, Catherine Boldig, Rob J B Macaulay, Arnold Etame, . Trends in treatment and survival among patients with glioblastoma in the United States, 2000 to 2020: A population-based SEER analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6632.