Background: Glioblastoma multiforme (GBM) is the most common type of malignant brain tumor accounting for 16% of all primary brain and central nervous system (CNS) neoplasms in the United States. Adults diagnosed with GBM have poor prognosis, with a median overall survival of 15 months. Prior research identified prognostic factors for GBM survival but lacked adjustments for comorbidity and was limited in sample size.
Objectives: To describe differences in survival by age, sex, race, and Elixhauser comorbidity score in GBM patients using Truveta’s real-world data (RWD).
Methods: This retrospective study used RWD from Truveta, a collective of 30 US health systems, representing 1 of 3 Americans. A total of 8,193 individuals 18 years or older were diagnosed with GBM between 2012–2022. Comorbidities were evaluated using Elixhauser score and bucketed into two groups: 0-3 and ≥3. Survival differences were assessed using univariable Kaplan Meier survival curves and adjusted with a multivariable cox proportional hazard model. The significance threshold for all models was α = 0.05. Data was analyzed using SparkR in Truveta Studio.
Results: Patients were primarily male (57% vs. 38% female) and white (73%). 10% were aged 18-44; 43% aged between 45-64, and 47% aged 65 years or older. 67% had an Elixhauser comorbidity score of ≥3.
Males had a lower survival probability compared to females (10.8 vs 11.5 months, p< 0.001). Significant differences in survival were observed by age groups (18-44 vs. 45-64 vs. 65 years or older), where older patients had a worse outcome (28 vs. 13.4 vs. 7.3 months, p< 0.001). Whites had a median survival of 11.1 months, compared to 30.8 months for Blacks. Patients with Elixhauser score of 0-3 had a median survival of 11.5 months compared to 10.7 months (score of ≥3).
Significant differences in sex, race and age remained when adjusting for covariates. Significantly higher hazard ratios (HR) were observed in males (HR = 1.12, 95% CI: 1.06-1.18, p< 0.001) compared to females. Patients aged 45-64 had a HR of 2.39 (95% CI: 2.14-2.66, p< 0.001), and patients aged 65 or older had a HR of 4.21 (95% CI: 3.76-4.71, p< 0.001). No significant differences were observed in groups with different Elixhauser scores.
Conclusions: GBM is a prevalent primary CNS tumor with unfavorable survival. This study showed that age, sex, and race are prognostic factors leading to significant survival disparities. Age yielded significant differences in survival probability; younger individuals have a higher median survival. Demographic factors remained significantly different when adjusted in the Cox model, though comorbidities were not.
Further work is needed to identify additional variables that impact outcomes in this population.
