title: The prognostic value of MGMT promoter status by pyrosequencing assay for glioblastoma patients' survival: a meta-analysis.
abstract: BACKGROUND
  The prognostic value of the status of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation measured by pyrosequencing assay (PSQ) among glioblastoma (GBM) patients was examined in meta-analysis.
  
  
  METHODS
  Eligible studies that reported the association between the status of MGMT promoter methylation by PSQ and prognostic value of GBM patients from three electronic databases, like PubMed, EMBASE, and Cochrane library were involved in meta-analysis. Using Stata 11.0, the summarized hazard ratios (HRs) for overall survival (OS) and the progression-free survival (PFS) with 95 % confidence interval (CI) were calculated.
  
  
  RESULTS
  Eleven studies were included to evaluate the relationship between the status of MGMT promoter methylation and GBM patients' survival. Overall, regardless of the cut-off value of methylation status of MGMT promoter by PSQ, methylated-positive patients were evidently associated with an improved HRs for OS (HRs = 0.50, 95 % CI = 0.35-0.66). For summary, progression-free survival (PFS) from four studies, the prognostic effect was also found (HRs = 0.56, 95 % CI = 0.32-0.80).
  
  
  CONCLUSIONS
  Methylation positivity of MGMT promoter by PSQ was related to an increased survival in GBM patients. Thus, the status of MGMT promoter methylation by PSQ might be used to be a prognostic biomarker, and GBM patients might have a vested interest in clinical application of standardized PSQ.
authors.forename: Hailong
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Neurology, The First Hospital of Yichang, Institute of Translational Neuroscience, Three Gorges University College of Medicine, Yichang, People's Republic of China.
authors.forename: Shuying
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Neurology, The First Hospital of Yichang, Institute of Translational Neuroscience, Three Gorges University College of Medicine, Yichang, People's Republic of China.
authors.forename: Chengwei
authors.initials: C
authors.lastname: Song
authors.affiliation: Department of Neurology, The First Hospital of Yichang, Institute of Translational Neuroscience, Three Gorges University College of Medicine, Yichang, People's Republic of China. Yunhong_Zhang2001@126.com.
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Zha
authors.affiliation: Wuhan Institute of Biological Products Co., Ltd., Wuhan, People's Republic of China. lily6161@yeah.net.
authors.forename: Li
authors.initials: L
authors.lastname: Li
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000009:adverse effects / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000235:genetics*; D001932:Brain Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000401:mortality*; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D003606:Dacarbazine / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use; D018572:Disease-Free Survival; D005909:Glioblastoma / Q000188:drug therapy / Q000235:genetics* / Q000401:mortality*; D006801:Humans; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA / Q000379:methods; D000077204:Temozolomide; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D018906:Antineoplastic Agents, Alkylating; D014408:Biomarkers, Tumor; D025521:Tumor Suppressor Proteins; D003606:Dacarbazine; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes; D000077204:Temozolomide
keywords: Glioblastoma; Hazard ratio; MGMT; Meta-analysis; Prognostic biomarker; Pyrosequencing; Survival