IDH1 and astrocytoma (excluding glioblastoma): In astrocytoma, median OS was reported to vary between 5.8 months in elderly patients (20) to 23.8 months in diffuse grade 4, IDH1/2 wildtype astrocytoma with molecular features of glioblastoma (22) and to 5.2 years for low-grade astrocytoma (12).