Isocitrate Dehydrogenase-Mutant Glioma: Evolving Clinical and Therapeutic Implications

The metabolic genes isocitrate dehydrogenase 1 (IDH1) and IDH2 are commonly mutated in low-grade glioma and in a subset of glioblastoma. These mutations co-occur with other recurrent molecular alterations, including 1p/19q codeletions and tumor suppressor protein 53 (TP53) and alpha thalassemia/mental retardation (ATRX) mutations, which together help to define a molecular signature that aids in the classification of gliomas and helps to better predict clinical behavior. A confluence of research suggests that glioma development in IDH-mutant and IDH wild-type tumors is driven by different oncogenic processes and responds differently to current treatment paradigms. Herein, the authors discuss the discovery of IDH mutations and associated molecular alterations in glioma, review clinical features common to patients with IDH-mutant glioma, and highlight current understanding of IDH mutation-driven gliomagenesis with implications for emerging treatment strategies. (C) 2017 American Cancer Society.