Clinical implications of molecular analysis in diffuse glioma stratification

In this study, we evaluated the molecular alterations for consecutive 300 diffuse glioma cases (grade 2, 56; grade 3, 62; grade 4, 182) based on this classification. Mutations in the isocitrate dehydrogenase (IDH) genes were common in lower grade glioma (LGG: grade2 –3), and when combined with 1p/19q status, LGGs could be stratified into three groups except for four cases (Astrocytoma, IDH-mutant: 44; Oligodendroglioma, IDH-mutant and 1p/19q codeleted: 37; Astrocytoma,IDH-wildtype: 33). 1p/19q-codeleted oligodendrogliomas were clinically the most favorable subgroup even with upfront chemotherapy. In contrast,IDH-wildtype astrocytomas had a relatively worse prognosis; however, this subgroup was more heterogeneous. Of this subgroup, 11 cases hadTERT promoter (pTERT) mutation with shorter overall survival than 12 pTERT-wildtype cases. Additionally, a longitudinal analysis indicated pTERT mutation as early molecular event for gliomagenesis. Therefore, pTERT mutation is critical for the diagnosis of molecular glioblastoma (WHO grade 4), regardless of histological findings, and future treatment strategy should be considered based on the precise molecular analysis.
Source: Brain Tumor Pathology - Category: Neurology Source Type: research