IDH2 and oligodendroglioma: Moreover, patients with diffuse astrocytoma IDH-mutant had a significantly shorter PFS (3.9 ± 0.5 years, 95%-CI: 2.8–4.9) than patients with oligodendroglioma IDH-mutant (5.8 ± 0.6 years, 95%-CI: 4.7–6.9; p = 0.04).