Implementation of Recent WHO Classification in Publications on Glioblastoma Research Using Multi-Omics Databases

(1) Background: Modifications to tumor classifications could fundamentally alter the foundation of research approaches. A concrete illustration of this issue is the actual WHO classification of tumors of the central nervous system, published in 2021. According to the WHO classification, GBM is an IDH wild-type tumor. However, some multi-omics databases retain the classification from the time the samples for the datasets were collected, prior to the WHO 2021 classification, including IDH mutant GBMs. We were interested in assessing the number of papers published in the biomedical literature from 2022 to 2025 that are based on these databases, to ensure the correct implementation of the WHO 2021 classification of GBM. (2) Methods: We systematically reviewed publications in the biomedical literature from 2022 to 2025 that utilized the two most widely used multi-omics databases in the glioma research field, the CGGA and TCGA databases, to assess the correct application of the classification of GBM. (3) Results: We identified 269 publications, but only 45 (14%) correctly included only IDH wild-type GBM; 83 (33%) also contained IDH mutant tumors; and 141 (53%) provided no information about the IDH status of their research material. (4) Conclusions: Using a systematic search strategy, we found that 1/3 of published papers used IDH mutant tumors, and 1/2 of the studies did not report the IDH status of the tumors.