Associations of O6-methylguanine-DNA methyltransferase promoter methylation status with age and 1p/19q codeletion status in isocitrate dehydrogenase mutation gliomas based on an Asian cohort: A narrative review

The expression of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) can lead to tumor cell resistance to alkylating agents. Glioblastomas with isocitrate dehydrogenase mutation (IDHmut) were reported to have significantly higher MGMT promoter methylation, which predicted improved outcomes after temozolomide treatment. However, the MGMT methylation status in IDHmut glioma remains controversial. To further explore the associations of MGMT promoter methylation status with other molecular features in IDHmut gliomas, in this work, we analyzed the relationship of MGMT promoter methylation status with 1p/19q codeletion status and age in IDHmut gliomas based on a large Asian (Chinese) cohort. We found that there was no significant difference in MGMT methylation status in IDHmut 1p/19q-codeleted oligodendrogliomas compared to IDHmut astrocytomas, in either primary or recurrent cases. Moreover, the MGMT methylation status was not associated with age. The difference compared to previous research which indicated the MGMT methylation status differed significantly among IDHmut glioma might be caused by differences between populations, indicating that routine assessment of MGMT methylation status in oligodendrogliomas may still be necessary.