A Population-Based Cohort Study of Glioblastoma (World Health Organization Grade 4 Gliomas) in Ontario: Continued Improvement in Care over 25 Years

Abstract

Objective

Grade 4 glioma is the most common and fatal primary malignant brain tumor in adults. We sought to describe the evolution of care and survival of patients with glioblastoma in a single-payer Canadian provincial health care system over a 24-year period.

Methods

Adult patients >18 years old with pathologically or clinically diagnosed glioblastoma (based on fourth or earlier edition of World Health Organization classification) in Ontario between 1994 and 2018 were identified and followed until death or study end point of 2 years through provincial administrative health data. Patient characteristics, type of treatment, survival, and time spent in the hospital were compared across time periods, age groups, and centers.

Results

We included 9487 patients with glioblastoma treated from 1994 to 2018. Median survival and 2-year survival rate improved over the study period from 6.4 to 9.4 months and 10% to 18%, respectively. Older age was associated with shorter survival (median survival of 12 months at 65–74 years vs. 3 months at > 85 years), less aggressive therapy, and a higher proportion of remaining lifetime spent in the hospital (more than one third of patients >75 years spend ≥50% their remaining survival in hospital). Time in the hospital decreased by 8.9 days (95% confidence interval 8.53–9.25) over the study period. Significant heterogeneity exists in patient management and outcome between regional treatment centers.

Conclusions

The real-world prognosis for grade 4 glioma remains poor. However, an increased proportion of patients receiving maximal therapy is associated with a small but meaningful improvement in survival and decreased time in the hospital for all but the oldest patients.