title: Prognostic value of MGMT methylation in colorectal cancer: a meta-analysis and literature review.
abstract: The development of colorectal cancer (CRC) spans about 5-10 years, making early detection and prevention beneficial to the survival of CRC patients. To address inconsistencies in evidence regarding O(6)-methylguanine-DNA-methyltransferase (MGMT) methylation as a potential prognostic factor in CRC, we conducted a meta-analysis to evaluate MGMT methylation in CRC patients. Fourteen studies were included in the meta-analysis after screening 120 articles. The following items were collected from each study: author, published year, country, patient gender, MGMT methylation status, and patients' disease progression. Pooled hazard ratios and odd ratios with 95% confidence intervals (CIs) were calculated using fixed or random effect models depending on the heterogeneity between studies. The overall survival of CRC patients was found not to be significantly associated with MGMT methylation. Further subgroup analysis showed that the frequency of MGMT methylation was significantly higher in CRC than in normal tissues (p < 0.00001). MGMT promoter in CRC patients was more frequently methylated than in adenoma patients. In addition, MGMT methylation was significantly increased in adenoma than in normal tissues (p < 0.0001). In conclusion, MGMT methylation is central to the development of cancer that involves a stepwise carcinogenesis of normal adenoma carcinoma cascade. However, MGMT methylation is not associated with the prognosis of CRC.
authors.affiliation: Department of Gastrointestinal Surgery, Shandong Provincial Cancer Hospital, Jinan, 250117, Shandong, China.
authors.forename: Yanliang
authors.initials: Y
authors.lastname: Li
authors.forename: Zhongchuan
authors.initials: Z
authors.lastname: Lyu
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Cheng
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhu
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiuwan
authors.initials: X
authors.lastname: Shang
authors.forename: Huaijie
authors.initials: H
authors.lastname: Shi
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D006801:Humans; D011379:Prognosis; D011401:Promoter Regions, Genetic; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes