Updating TCGA glioma classification through integration of molecular profiling data following the 2016 and 2021 WHO guidelines

The understanding of glioma disease has been evolving drastically with the dedicated research into the genetic and molecular profiling of glioma tumour tissue. Molecular biomarkers have gained progressive and substantial importance in providing diagnostic information, leading to groundbreaking changes in the tumour classification system and taxonomy standardised by the 2016 and 2021 editions of the World Health Organization (WHO) Classification of Tumours of the Central Nervous System's guidelines. Some of the insights into glioma disease derived from extensive research on open-source multi-omics databases, such as the Cancer Genome Atlas (TCGA). However, given the substantial changes in glioma classification, these retrospective data may harbour outdated diagnostic annotations, suboptimal for further research. Here we propose two methods for updating the tumour classification of TCGA adult glioma samples in accordance with the 2016 and 2021 WHO Classification of Tumours of the Central Nervous System, through the integration of curated molecular profiling information provided by a study from TCGA Research Network. Overall, our methods determine the change in the patient-specific glioma diagnosis. The glioma reclassification of the publicly available datasets can support further bioinformatic and statistical analyses of updated glioma subtypes. ### Competing Interest Statement The authors have declared no competing interest.