Objective: Rs1495741 has been identified to infer N-acetyltransferase 2 (NAT2) acetylator phenotype, and to decrease the risk of bladder cancer. However, a number of studies conducted in various regions showed controversial results. To quantify the association between rs1495741 and the risk of bladder cancer, and to estimate the interaction effect of this genetic variant with smoking, we performed a systematic literature review and meta-analysis involving 14815 cases and 58282 controls from 29 studies.
Methods: A comprehensive online search was conducted on Pubmed, Embase, Web of Science, WanFang Data. The association strength of rs1495741 and bladder cancer risk was measured by odds ratio (OR) with 95% CI. The association between bladder cancer and smoking status of the included populations were first estimated by pooled OR. Then the interaction of rs1495741 and smoking was investigated by stratified analysis by smoking habits (ever and never smoking groups).
Results: Our results indicates rs1495741 significantly associated with bladder cancer risk (OR =0.85, 95% CI =0.82–0.89, test for heterogeneity P=0.36, I2 =7.0%). And we verified this association in populations from Europe, America and Asian. Further, our stratified meta-analysis showed rs1495741’s role is typically evident only in ever smokers, which suggesting its interaction with smoking.
Conclusions: Our systematic review and meta-analysis indicates the association of SNP rs1495741, smoking and bladder cancer risk in populations from Europe, America and Asia. And we confirmed this association in ever smoker population only, which suggests the underlying mechanism of this association could be rs1495741’s role as a tag SNP of NAT2 acetylation phenotype. Our results may provide new insights in gene-environmental study on bladder cancer.
