title: Noninvasive DNA methylation biomarkers in colorectal cancer: A systematic review.
abstract: OBJECTIVE
  To summarize the current evidence on the biomarkers associated with DNA methylation in the screening and diagnosis of colorectal cancer (CRC).
  
  
  METHODS
  A literature search was conducted on the databases of PubMed and Web of Science to identify articles published from 1 January 2000 to 6 June 2015 with language striction. Stuides focusing on the association between noninvasive biomarkers indicating DNA methylation and CRC were included.
  
  
  RESULTS
  Altogether 74 studies were finally included in the study. Varied genetic markers in the feces and blood samples were hypermethylated in patients with CRC than in the healthy controls. Some of them could even be detected at the early stage of the tumors. The sensitivity of the genetic markers was superior to that of fecal occult blood test and carcinoembryonic antigen. Multitarget DNA assays using a combination of different methylated genes could improve the diagnostic sensitivity.
  
  
  CONCLUSIONS
  Genetic markers might be minimally invasive, economical and accurate for the screening and surveillance of CRC. Large multicenter studies evaluating these biomarkers systematically and prospectively not only in CRC but also in other types of cancers are needed in the future.
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University.|Institute of Gastroenterology, Zhejiang University.
authors.forename: Meng
authors.initials: M
authors.lastname: Xue
authors.affiliation: Institute of Gastroenterology, Zhejiang University.|Department of Gastroenterology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China.
authors.forename: San Chuan
authors.initials: SC
authors.lastname: Lai
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University.
authors.forename: Zhi Peng
authors.initials: ZP
authors.lastname: Xu
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University.|Institute of Gastroenterology, Zhejiang University.
authors.forename: Liang Jing
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D015179:Colorectal Neoplasms / Q000097:blood / Q000235:genetics*; D019175:DNA Methylation / Q000235:genetics*; D055088:Early Detection of Cancer / Q000379:methods; D005243:Feces; D005819:Genetic Markers; D006801:Humans; D009780:Occult Blood; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D005819:Genetic Markers
keywords: DNA methylation; colorectal neoplasms; screening