IDH1 and oligodendroglioma: For instance, patients with glioblastoma in the non-TCGA cohort had a median survival of 19.0 months, exceeding the median survival of 15.0 months observed in previous clinical trials and in the TCGA cohort.26 In comparison, IDH1/2-mutant astrocytomas and oligodendrogliomas have seen more significant increases in median survival during the contemporary period: non-TCGA IDH1/2-mutant astrocytoma patients had a median survival of 11.4 years while the median survival for oligodendrogliomas was 25.6 years.