The association of NAT1 polymorphisms and colorectal carcinoma risk: evidence from 20,000 subjects.

Published data on the association between N-acetyltransferase 1 (NAT1) gene polymorphisms and colorectal carcinoma (CRC) susceptivity are inconclusive. To derive a more precise estimation of the association, we conducted this meta-analysis. Data were collected from electronic databases: PubMed, EMBASE, with the last report up to May 2010. The odds ratio (OR) and corresponding 95% confidence intervals (CIs) were used to assess the strength of the association. A total of 20 individual studies including 8,219 cases and 11,498 controls based on the search criteria were involved. Meta-analysis was performed for slow versus rapid acetylation genotypes of NAT1. We found no association between NAT1 polymorphisms and CRC in overall population (OR = 0.96, 95% CI = 0.88-1.05 P = 0.05 for heterogeneity) without significant publication bias present. In subgroup analyses, similar results were found in different ethnicities, source of controls, genotyping methods and adjustment. Current meta-analysis suggests that lack of association between the NAT1 polymorphisms and individual risk to CRC.