Exploring the Relationship Between Risk Signature and Genomic Alterations

According to the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy, genomic events, such as telomerase reverse transcriptase promoter (TERTp) mutation, the combination of whole chromosome 7 gain and whole chromosome 10 loss (chr 7+/10-), epidermal growth factor receptor amplification, and O-6-methylguanine-DNA-methyltransferase promoter (MGMTp) methylation status, are closely related to survival outcomes (Geisenberger et al., 2015; Brat et al., 2018). These markers could not be used to establish the prognostic model in this study, as that would jeopardize validation in the CGGA cohort. However, the relationship between them and the risk signature was analyzed to explore a more comprehensive potential network. In line with earlier reports (Galbraith et al., 2020), the detection rate of TERTp mutations was too low to allow direct evaluation of its prognostic value in the TCGA cohort. To overcome this problem, we used TERT gene expression as a proxy for TERTp mutation status (Galbraith et al., 2020). Traditionally, MGMTp methylation status is an important common biomarker, but the TCGA cohort could not directly provide relevant information, compelling the use of MGMT methylation level to represent MGMTp status (Cai et al., 2021).