MGMT and neoplasm: Although independent factors, i.e., age, preoperative Karnofsky performance scale (KPS), molecular markers (IDH-1 mutation, O6-methylguanin-DNA-methyltransferase, MGMT, promoter methylation), and tumor location, might play a role in influencing OS, EoR is the variable that we as neurosurgeons can influence [12, 43].