termsTerm
MGMT promoter methylation
A chemical switch that turns off a DNA-repair gene. When it is off, temozolomide works much better.
O6-methylguanine-DNA methyltransferase repairs the lesion temozolomide creates; promoter methylation silences it in ~40% of glioblastomas. Methylated: median OS ~23 months with chemoradiation; unmethylated: ~13 months with minimal temozolomide benefit, so unmethylated patients are the priority for novel-agent trials (e.g., CheckMate 498, which failed). Assay (MSP, pyrosequencing, methylation array) and cut-off variability persist.
Biomarkers: what this kind of term is about · animated schematic, not to scale
Category
Biomarkers