MGMT and glioblastoma: The results of subgroup analysis showed that patients with methylated MGMT in extended group had significantly longer OS and PFS than those in control group; patients with IDH1 mutation benefited more from extended adjuvant TMZ chemotherapy than those with wild-type IDH1; there was no significant difference in the effect of extended TMZ chemotherapy on OS between GBM patients with wild-type p53 and those with mutant p53; compared with GBM patients with lower expression of Ki67, extended adjuvant TMZ treatment dramatically improved the OS and PFS of those with higher expression of Ki67.