A Meta-Analysis of the Relationship Between NAT 2 Polymorphism and Colorectal Cancer Susceptibility

Background and Objective. Although the association between N-acetyltransferase 2 (NAT2) polymorphism and colorectal cancer (CRC) susceptibility in humans has been extensively investigated, the results are contradictory. The aim of this study was to conduct a meta-analysis of published studies to quantitatively summarize the association between NAT2 polymorphism and risk of CRC. Material and Methods. Relevant studies that had investigated NAT2 polymorphism and CRC susceptibility were identified through a comprehensive search of Pubmed, EMBASE, Medline, Biosis, Wiley-Blackwell, ISI Web of Knowledge, CNKI, and Chinese Biomedicine Database until October 2011. After selection based on the inclusion and exclusion criteria, the relevant data were extracted from each study, and finally a meta-analysis was performed. Results. Eight phenotype studies (791 cases and 1158 controls) and 45 genotype studies (13 875 cases and 18 879 controls) were included in the present meta-analysis. The pooling of phenotype studies showed no significant association between the NAT2 acetylator status and CRC susceptibility (rapid acetylator, OR, 1.32; 95% CI, 0.92–1.89, P=0.14; slow acetylator, OR, 0.76; 95% CI, 0.53–1.09, P=0.14). The combined ORs for rapid and slow acetylator status and CRC risk in genotype studies were 1.01 (95% CI, 0.94–1.08; P=0.86) and 0.99 (95% CI, 0.93–1.06; P=0.86), respectively. In the subgroup analysis by regions, no increased risks were found in Asians, Europeans, Americans, or Australasians. Pooling studies were also conducted on the groups of gender, specific tumor sites, and smoking status, but no significant association in genotype distribution between CRC and control was found as well. Conclusions. These results of our meta-analysis suggest that there is no overall association between NAT2 polymorphism and CRC susceptibility