RT Journal Article SR Electronic T1 Predictive value of MGMT promoter methylation on the survival of TMZ treated IDH-mutant glioblastoma JF Cancer Biology and Medicine JO Cancer Biol Med FD China Anti-Cancer Association SP 271 OP 282 DO 10.20892/j.issn.2095-3941.2020.0179 VO 18 IS 1 A1 Chai, Ruichao A1 Li, Guanzhang A1 Liu, Yuqing A1 Zhang, Kenan A1 Zhao, Zheng A1 Wu, Fan A1 Chang, Yuzhou A1 Pang, Bo A1 Li, Jingjun A1 Li, Yangfang A1 Jiang, Tao A1 Wang, Yongzhi YR 2021 UL http://www.cancerbiomed.org/content/18/1/271.abstract AB Objective: O6methylguanine-DNA methyltransferase (MGMT) promoter methylation is a biomarker widely used to predict the sensitivity of IDH-wildtype glioblastoma to temozolomide therapy. Given that the IDH status has critical effects on the survival and epigenetic features of glioblastoma, we aimed to assess the role of MGMT promoter methylation in IDH-mutant glioblastoma.Methods: This study included 187 IDH-mutant glioblastomas and used 173 IDH-wildtype glioblastomas for comparison. Kaplan-Meier curves and multivariate Cox regression were used to study the predictive effects.Results: Compared with IDH-wildtype glioblastomas, IDH-mutant glioblastomas showed significantly higher (P < 0.0001) MGMT promoter methylation. We demonstrated that MGMT promoter methylation status, as determined by a high cutoff value (≥30%) in pyrosequencing, could be used to significantly stratify the survival of 50 IDH-mutant glioblastomas receiving temozolomide therapy (cohort A); this result was validated in another cohort of 25 IDH-mutant glioblastomas (cohort B). The median progression-free survival and median overall survival in cohort A were 9.33 and 13.76 months for unmethylated cases, and 18.37 and 41.61 months for methylated cases, and in cohort B were 6.97 and 9.10 months for unmethylated cases, and 23.40 and 26.40 months for methylated cases. In addition, we confirmed that the MGMT promoter methylation was significantly (P = 0.0001) correlated with longer OS in IDH-mutant patients with GBM, independently of age, gender distribution, tumor type (primary or recurrent/secondary), and the extent of resection.Conclusions: MGMT promoter methylation has predictive value in IDH-mutant glioblastoma, but its cutoff value should be higher than that for IDH-wildtype glioblastoma.