High grade glioma is a rapidly progressive form of brain tumour: half of all patients will die within a year of diagnosis even after treatment with surgery and radiotherapy

High grade glioma (HGG) is a rapidly progressive form of brain tumour with a poor survival rate even after treatment with surgery and radiotherapy. We found two trials, enrolling 703 patients in total with a newly diagnosed glioblastoma multiforme (a form of HGG), that studied chemotherapy with temozolomide during and after radiotherapy. This was compared with radiotherapy only. Those who received temozolomide had an improved survival and delayed time to recurrence. The short term adverse events associated with temozolomide are low but can be severe, while the long term effects are unknown. In recurrent disease a single trial was identified that included 225 patients with glioblastoma multiforme at first relapse. In this instance temozolomide delayed progression but did not improve overall survival. No RCTs investigated the use of temozolomide in HGGs other than glioblastoma multiforme. All these trials enrolled highly selected patients with good prognostic features that are not entirely reprasentative of all patients with glioblastoma multiforme limiting the general applicability of these results.