N-acetyltransferase 2 phenotype and risk of esophageal cancer: a meta analysis

N-acetyltransferase 2 (NAT2) gene encodes a phase II enzyme taking part in detoxification of aromatic amines. Published studies have demonstrated that N-Acetyltransferase 2 (NAT2) phenotype is a risk factor of various cancers. Many studies have investigated the association between NAT2 phenotype and susceptibility to esophageal cancer but yielded controversial results. To derive a more precise estimation of this association, a meta-analysis was performed. Electronic databases (Pubmed/Medline, ISI Web of Science and China National Knowledge Infrastructure) in English and Chinese were searched. A total of 5 articles including 476 cases and 1,093 controls were included in this meta-analysis. Odds ratio (OR) with 95% confidence interval (95% CI) was used to evaluate intensity of associations. Pooling studies together, NAT2 slow acetylator phenotype was a significant risk factor of esophageal squamous cell cancer (OR=1.35, 95% CI=1.03-1.77, n=5 studies) but not esophageal adenocarcinoma (OR=0.97, 95% CI=0.47-2.04, n=2 studies). There was a significant association between NAT2 acetylator phenotypes and ESCC in South Asian populations (OR=1.51, 95% CI=1.03-2.20), but not in East Asian populations (OR=1.19, 95% CI=0.80-1.77). Significant association between NAT2 acetylator phenotypes and esophageal cancer was found in population-based control subgroup (OR=1.63, 95% CI=1.07-2.50) but not in hospital-based control subgroup (OR=1.19, 95% CI=0.84-1.69). There is a significant association between NAT2 acetylator phenotype and esophageal cancer in both smokers (OR=1.681, 95% CI=1.179-2.395) and non-smokers (OR=1.614, 95% CI=1.173-2.222). In conclusion, NAT2 slow acetylator phenotype was a significant risk factor of ESCC in Asian populations.