title: Absence of association between N-acetyltransferase 2 acetylator status and colorectal cancer susceptibility: based on evidence from 40 studies.
abstract: OBJECTIVE
  N-Acetyltransferase (NAT) 2 is an important enzyme involved in the metabolism of different xenobiotics, including potential carcinogens, whose phenotypes were reported to be related to individual susceptibility to colorectal cancer (CRC). However, the results remain conflicting. To assess the relationship between NAT2 phenotypes and CRC risk, we performed this meta-analysis.
  
  
  METHODS
  A comprehensive literature search was conducted to identify all case-control or cohort studies of NAT2 acetylator status on the susceptibility of CRC by searching of PubMed and EMBASE, up to May 20, 2011. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association.
  
  
  RESULTS
  A total of over 40,000 subjects from 40 published literatures were identified by searching the databases. No significantly elevated CRC risk in individuals with NAT2 slow acetylators compared with fast acetylators was found when all studies pooled (OR = 0.95, 95% CI: 0.87-1.04, I(2) = 52.6%). While three studies contributed to the source of heterogeneity were removed, there was still null result observed (OR = 0.96, 95% CI: 0.90-1.03, P = 0.17 for heterogeneity, I(2) = 17.8%). In addition, we failed to detect any associations in the stratified analyses by race, sex, source of controls, smoking status, genotyping methods or tumor localization. No publication bias was observed in this study.
  
  
  CONCLUSIONS
  This meta-analysis suggests that the NAT2 phenotypes may not be associated with colorectal cancer development.
authors.affiliation: Colorectal and Anal Surgery Center, The Affiliated Jiangsu Cancer Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Lou qian
authors.initials: Lq
authors.lastname: Zhang
authors.forename: Jian nong
authors.initials: Jn
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Guo dong
authors.initials: Gd
authors.lastname: Liang
authors.forename: Jing ying
authors.initials: Jy
authors.lastname: Li
authors.forename: Yi dan
authors.initials: Yd
authors.lastname: Zhu
authors.forename: Yun tao
authors.initials: Yt
authors.lastname: Su
mesh_terms: D000107:Acetylation; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D017594:Publication Bias; D012306:Risk
chemical_list: D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human