Improving prognosis of glioblastoma in the 21st century: who has benefited most?

Abstract

Background: Glioblastoma multiforme (GBM) is the most frequent primary brain tumor in adults. Temozolomide was rapidly incorporated into first-line treatment following the publication of the pivotal European Organization for Research and Treatment of Cancer-National Cancer Institute of Canada phase 3 trial in 2005. However, in the trial, enrollment was limited to younger patients with good performance status. Therefore, this study performed a population-based survival analysis of patients with newly diagnosed GBM covering the period before and after the introduction of temozolomide.

Methods: Survival statistics and clinical and demographic variables were extracted from the Survival, Epidemiology and End Results Database for patients diagnosed with GBM from 2001 to 2007. Mean regional income for each patient was also collected. Survival was analyzed using the Kaplan-Meier method and proportional hazard models.

Results: A total of 13,003 adult patients diagnosed with a GBM were identified. Prognostic variables included age <70 years, use of radiation, gross total resection, and residence in a high-income district (P < .001). Between 2001 and 2007, the median survival time increased from 7 to 9 months for the entire population. The 1-year survival increased from 29% to 39%. Prognosis of patients aged 70 or more years did not improve over this time. Over the study period, the absolute disparity in 1-year survival between low- and high-income districts increased from 6.6% to 10.1%.

Conclusions: There has been a stepwise improvement in the overall survival of patients with GBM between 2001 and 2007. This improvement has been confined to patients <70 years of age and has been most prominent among patients living in high-income districts.