Central nervous system tumours are the most common cause of cancer-related deaths and disability in children and young people. Approximately half of all childhood brain tumours fall into the subtype of ‘glioma’. Gliomas are the largest group of childhood brain tumours with distinct biology from that seen in adults. The recently revised World Health Organisation (WHO) Central Nervous System (CNS) Tumour Classification (WHO CNS5 2021) has now divided diffuse gliomas into adult-type and paediatric types as well as establishing the role of molecular testing in producing a new integrated diagnosis including novel diagnostic technologies such as DNA methylome profiling. CNS5 has introduced several new paediatric glioma entities, many with distinct molecular drivers, but there remains a lack of correlative patient outcome data to assess the real clinical impact of the new classification.

This project will utilise the extensive retrospective cohort of paediatric gliomas at Great Ormond Street Hospital for which we have rich clinical data collected as standard-of-care. It will seek to recall and re-analyse samples using current molecular techniques: using the WHO CNS5 2021 to reclassify the tumour diagnosis, update the existing clinical glioma database, and enable statistical correlation with survival and patient outcomes to allow “real world” data analysis and assess the clinical impact of the revised molecular-based classification.