Diagnostic and prognostic markers in gliomas

Purpose of review This review summarizes recent studies on diagnostic and prognostic markers in gliomas such as the BRAF fusion gene in pilocytic astrocytomas and 1p/19q codeletion, O-6-methylguanine-DNA methyltransferase status and isocitrate dehydrogenase 1 (IDH1)/IDH2 mutations in diffuse gliomas. Recent findings In pilocytic astrocytomas, the BRAF fusion gene has been recently identified as a specific and frequent event leading to potentially targetable mitogen-activated protein kinase pathway activation. In grade II/III gliomas and in glioblastomas, chromosome 1p/19q codeletion and O-6-methylguanine-DNA methyltransferase status remain the most important prognostic and predictive markers. Recently identified mutations in IDH1/IDH2, however, are specific for diffuse gliomas, occur frequently in grade II/III gliomas and are of prognostic value in grade III gliomas, as well in glioblastomas in which they characterize secondary glioblastomas. Summary Extensive molecular studies have enabled the discovery of new diagnostic and prognostic markers that are refining the histomolecular classification of gliomas.