MGMT methylation status may predict survival in elderly patients with newly diagnosed glioblastoma (GBM)
e13023 Background: Methylation of the MGMT gene promoter is associated with prolonged survival and response to temozolomide in GBM < 70. However, it is unclear if MGMT is a useful prognostic biomarker in the elderly GBM population who traditionally are viewed as less responsive to treatment. Methods: We retrospectively reviewed MGMT promoter methylation status and clinical characteristics in patients 70 years or older with newly diagnosed GBM undergoing resection at our institution from 1998–2008. MGMT analysis was performed by extracting tumor genomic DNA for bisulfite conversion. MGMT methylation specific PCR (MSP) was then performed using PCR primer sets specific for methylated and unmethylated MGMT promoter sequence. The logrank test was used to compare mPFS and mOS in patients who had methylated (ME) MGMT vs. unmethylated (UN) MGMT. Results: Thirty-four patients were included in the analysis. Twenty patients (59%) were ME while 14 (41%) were UN. Patients were treated with multimodality treatment (radiation + chemotherapy), radiation alone, or chemotherapy alone. ME was associated with a significantly prolonged mPFS and mOS as noted in the table below which also summarizes the characteristics of the study population. Conclusions: MGMT methylation status is associated with prolonged PFS and OS in elderly patients with newly diagnosed GBM. Knowledge of MGMT status may help improve prognostication in this patient population. [Table: see text] [Table: see text]