High-grade brain tumours are largely incurable. They arise in the brain, or start elsewhere and metastasise to the brain. Despite most people having a poor prognosis some individuals live considerably longer. To improve the outcome for all individuals, my research centres on finding prognostic markers that can predict, when the tumour is first diagnosed, how a tumour will develop. The aim of this study is to find genetic markers that will identify patients at risk of developing metastases in the brain, and for those that have primary brain tumours to find markers that predict survival, the rate of tumour progression, and response to treatment. This research uses novel categorisation of brain tumours into distinct groups based on two key cancer promoting pathways (telomere maintenance and p53 deregulation), which will from the basis for better understanding survival variation to identify informative markers.