N-acetyltransferase 2 genetic variants confer the susceptibility to head and neck carcinoma: evidence from 23 case–control studies

Previous evidence indicated that N -acetyltransferase 2 (NAT2) polymorphisms might be a risk factor for several cancers. A number of studies have been conducted on the association between NAT2 polymorphisms and head and neck cancer (HNC) risk. Nevertheless, the results were conflicting. Published meta-analysis on this issue has generated inconclusive results. Thus, we aimed to derive a more precise estimation of the relationship by conducting an updated meta-analysis. Published data prior to August 2013 have been searched and screened. Subgroup analysis on ethnicity, source of controls, sample size, and genotyping method were also performed. As a result, a total of 23 case–control studies including 4,028 cases and 4,872 controls were selected for analysis. Interestingly, the results showed that NAT2 polymorphisms might increase HNC risk for the overall data (OR 1.23, 95 % CI 1.01–1.49). Moreover, in subgroup analyses according to ethnicity, data showed that slow acetylators might increase HNC susceptibility among Asians (OR 1.78, 95 % CI 1.27–2.49), but not among Caucasians or mixed ethnicities. In conclusion, NAT2 polymorphism might be a low-penetrant risk factor for HNC among Asians.