Controversies in the treatment of elderly patients with newly diagnosed glioblastoma

Abstract

Approximately half of all patients with glioblastoma are older than 65 years and nearly one-quarter are older than 70 years, with a rising incidence of this disease in the elderly population. The life expectancy of elderly patients with glioblastoma is significantly shorter than in younger patients. Potential explanations for this abbreviated survival include differences in tumor biology, reduced use of therapies, enhanced toxicity of treatment, or diminished efficacy of available therapies with increasing age. The current standard treatment of newly diagnosed, protocol-eligible, nonelderly patients with glioblastoma is based on the randomized prospective EORTC/NCIC study that included patients aged 18 to 70 years with a performance status of ECOG 0 to 2. Limited single-institution retrospective series suggest that clinically fit elderly patients may benefit from a similar treatment regimen. However, no randomized trial has been performed in the elderly population using this regimen. Available prospective randomized clinical trials in the elderly population with glioblastoma have shown that radiotherapy is superior to supportive care only, that single-modality hypofractionated radiotherapy (reduced dose and shorter treatment schedule) is an alternative to single-modality standard fractionated radiotherapy, and that single-agent temozolomide is equivalent to radiotherapy alone. This article summarizes published data of current patterns of care in elderly patients and reviews published evidence as it pertains to the benefit of different treatment modalities in elderly patients with glioblastoma. Notwithstanding the previously mentioned randomized trials, the optimal treatment of elderly patients with glioblastoma remains controversial.