Role of <i>MGMT</i> Methylation Status at Time of Diagnosis and Recurrence for Patients with Glioblastoma: Clinical Implications

<i>MGMT</i> methylation presents relative stability during the clinical course of GBM. <b><i>The Oncologist</i></b> 2017;22:432-437 IMPLICATIONS FOR PRACTICE: <i>MGMT</i> methylation is a prognostic factor in newly diagnosed glioblastoma. In this study, we evaluated the rate of change of <i>MGMT</i> methylation during the clinical course of the disease, and we found a significant concordance between the first and the second <i>MGMT</i> methylation assessments, with <i>MGMT</i> methylation being stable in 75% of the cases. Thus, re-testing this biomarker at recurrence does not provide further information for clinicians. <i>MGMT</i> methylation at first surgery, extent of resection at second surgery, and time between first and second surgery are significantly correlated with overall survival. Age and extent of resection are correlated with post-progression survival.