Open AccessIdentifying the optimal cutoff point for MGMT promoter methylation status in glioblastoma
Author(s) -
Ngan Thi Kim Nguyen,
Jordan Redfield,
Matthew T. Ballo,
Madison Michael,
Jeffrey Sorenson,
Daniel T. Dibaba,
Jim Y. Wan,
Glenda Maria Delgado Ramos,
Manjari Pandey
Publication year - 2021
Publication title -
cns oncology
Language(s) - English
Resource type - Journals
eISSN - 2045-0915
pISSN - 2045-0907
DOI - 10.2217/cns-2021-0002
Subject(s) - glioblastoma , methylation , medicine , oncology , cutoff , dna methylation , cancer research , biology , genetics , gene , physics , gene expression , quantum mechanics
Aim: To define the optimal cutoff point for determining methylation status of O6-methylguanine-DNA methyltransferase (MGMT) by pyrosequencing in glioblastoma. Patients & methods: A retrospective study of 109 glioblastoma patients was performed to determine the optimal cutoff point for MGMT methylation status. Results: Receiver operating characteristic (ROC) analysis revealed 21% as the optimal cutoff (sensitivity: 68%; specificity: 59%) for MGMT methylation corresponding with the highest likelihood ratio of 1.66 and accuracy of 0.65. Methylation status (hazard ratio: 0.453; 95% CI: 0.279–0.735; p = 0.001) was associated with better overall survival. The crude model indicated linearity between methylation percent and survival rate; an increase of 10% of methylation resulted in a reduction of risk of death by 20% (p = 0.004). Conclusion: ROC analysis determined 21% as the optimal cutoff point for MGMT methylation status by pyrosequencing.