MGMT and glioblastoma: Notably, the negative impact of prolonged OTT was significantly more pronounced in the MGMT-methylated subgroup (p for interaction = 0.018), suggesting a biologically distinct vulnerability to treatment delays.<h4>Conclusions</h4>This study demonstrates that prolonged OTT and radiotherapy interruptions are independently associated with inferior survival in patients with IDH-wild-type glioblastoma, particularly in biologically favorable subgroups such as MGMT-methylated tumors.