**2. Twenty-first century epidemiological trends**

The most recent 2015 Statistical Report of the Central Brain Tumor Registry [1] documents the epidemiology of glioblastomas from 2008 to 2012. Glioblastomas remain the most common malignant histology (46.1%) of all primary malignant brain tumors, with an age-proportion‐ al incidence peaking at the ninth decade of life (age range 75-84 years). Of interest, glioblas‐ tomas have been shown to be 1.6 times more common in males, twice as common in Caucasians, and only 5.1% of patients survive five years after diagnosis.
