Glioblastoma survival: has it improved? Evidence from population-based studies

Glioblastoma is the most common malignant brain tumor in adults and carries a particularly poor prognosis. Since 2005, state-of-the-art therapy consists of maximal well tolerated surgical resection followed by combined radiotherapy and chemotherapy with temozolomide. Over the past decade, further advances have been achieved in various disciplines, most prominently including antiangiogenic treatment with bevacizumab. Still, whether these therapeutic innovations have translated to the general population remains unclear.

Population-based outcome and pattern of care (POC) studies have recently documented the rapid dissemination of the treatment standard to community practice across countries. This has resulted in a modest but significant increase in survival at the population level. However, the increase was significantly less marked in elderly patients in whom undertreatment is a concern. Other serious concerns address diverging POC between academic versus nonacademic centers, patients with high-income versus low-income, and racial and marital status disparities. With regard to bevacizumab treatment, there is still insufficient evidence of a beneficial impact on population-based survival, so far.

Despite the rapid incorporation of the current standard treatment in clinical practice and the thereby achieved modest survival gain at the population-level, prevailing POC needs to be reconsidered and standardized, especially for elderly glioblastoma patients who bear a large disease burden and carry the worst prognosis. Future POC studies are urgently needed and would benefit from the systematic inclusion of quality-of-life data and molecular tumor markers, so that this information could be captured in population-based cancer registries.