Sponsored by
MGMT promotor methylation status in glioblastoma is usually determined by molecular testing of tumor tissue samples, but testing methods and cutoff values vary across institutions. This study re-examined data from previous clinical trials of elderly glioblastoma patients using a strict definition of "unmethylated" (added safety margin below a main cutoff point to define "truly unmethylated" MGMT promotor) to determine the effectiveness of temozolomide (TMZ). Unsurprisingly, results showed that patients with truly unmethylated MGMT promotor status did not benefit from TMZ. This study concludes that validated, assay-specific methylation cutoffs should be applied in clinical trials and that better stratification of MGMT methylation status in clinical management will reduce toxicity without compromising outcomes for patients.