Introduction:Glioblastoma is the most common primary tumour of the CNS, and accounts for 12–15% of all intracranial tumours and 50–60% of gliomas.
Emergence of this Test:Typically, patients diagnosed with glioblastoma die within a few months if untreated.
MGMT ( O6-methylguanine-DNA methyltransferase) enzyme is a DNA repair enzyme that removes harmful alkyl groups from DNA.
This is a non-IHC test, usually done using methylation-specific PCR (MSP), or more accurately (and uncommonly) by pyrosequencing.
The European Organization for Research and Treatment of Cancer (EORTC) 26981-22981–National Cancer Institute of Canada (NCIC) randomized trial demonstrated that the survival benefit derived from combined radiotherapy and temozolomide chemotherapy is higher in patients whose tumours show methylation of MGMT than in those whose tumours have an unmethylated MGMT promoter.
Indications of MGMT ( O6-methylguanine-DNA methyltransferase)Test:
1. High grade glioma (anaplastic astrocytoma or glioblastoma)
2. Glioma* patient being considered for temozolamide therapy
*Glioma- a malignant tumour of the glial tissue of the nervous system.