title: Predictive value of MGMT promoter methylation status in Asian and Caucasian patients with malignant gliomas: a meta-analysis.
abstract: BACKGROUND
  The prognostic significance of O6-methylguanine-DNA methyltransferase (MGMT) promoter status for survival of patients with malignant gliomas remains controversial. Thus, the meta-analysis was performed in order to identify the impact of MGMT expression on prognosis of malignant gliomas.
  
  
  METHODS
  An extensive literature search for relevant studies was conducted on PubMed, Embase, Web of Science, Cochrane Library, and CBM databases. Version 12.0 STATA software was used for the current meta-analysis. Hazard ratios (HRs) with their corresponding 95% confidence interval (95% CI) were also calculated to clarify the correlation between MGMT expression and the prognosis of malignant gliomas.
  
  
  RESULTS
  Final analysis of 2,377 malignant gliomas patients from 32 clinical studies was performed. The meta-analysis results show that MGMT promoter group and unmethylated MGMT group has a significant difference (all P < 0.01). Combined HR of MGMT suggests that the methylated MGMT group has a longer overall survival than the unmethylated MGMT group (P < 0.01), but the Asians don't present a difference between the two groups.
  
  
  CONCLUSIONS
  The meta-analysis study shows that the elevated MGMT promoter group may have a better prognosis in malignant gliomas patients, but the Asians don't have a better prognosis.
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Ren
authors.affiliation: Department of Medical Oncology of PLA Cancer Center, 81 Hospital of PLA Nanjing 210002, China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Huai
keywords: MGMT; Malignant gliomas; O6-methylguanine-DNA methyltransferase; meta-analysis; prognosis; temozolomide