The methylation of the MGMT promoter was correlated with younger patients who were aged less than 39 years (OR 2.56, 95% CI 1.48–4.43), female (OR 1.52, 95% CI 1.11–2.08) or had an IDH1 mutation (OR 15.92, 95% CI 7.30–34.75) and an oligodendroglioma diagnosis (OR 6.20, 95% CI 1.33–28.88). This evidence concerns the gene IDH1 and oligodendroglioma.