N-acetyltransferase 2 (NAT2) genotypes,passive and active smoker and risk of breast cancer

Background: Breast cancer is the most common malignancy of women in the world. The disease is caused by infectious and non-infectious, environmental and lifestyle factors.Women who smoke at breast cancer diagnosis have higher risk of breast cancer-specific and all-cause mortality than nonsmokers. N-acetyltransferases (NATs) are important catalytic enzymes that metabolize carcinogenic arylamines. NAT2 genotype might modify the role of cigarette smoking, a source of arylamine exposure, in breast cancer. We conducted a study to investigate the association between NAT2 genotype, smoking and breast cancer risk Methods: : we performed systematic review of literature with related keywords in PubMed,Science direct and Google scholar to gather information in articles published since 2016 and summarized here Results: 347 women diagnosed (2002-2004) with breast cancer and 775 population-based controls. The mailed study package included a questionnaire requesting information aboutestablished breast cancer risk factors, passive and active smoking, and a buccal swab for genetic analyses. Among never-active smokers, a long duration of passive smoking was associated with an increased risk of breast cancer (odds ratio (OR) 1.86 (95% confidence interval (95% CI) 1.01- 3.44) (test for trend (p=0.07)); that risk was more elevated for NAT2 slow acetylators (OR 2.76, 95% CI 1.16-6.59) (and highest in extremely slow acetylators), but not elevated for NAT2 fast acetylators (OR 1.17, 95% CI 0.42-3.23). Among active smokers more than 20 pack-years of smoking was associated with an OR of 1.34 (95% CI 0.92-1.96); more elevated among NAT2 fast acetylators OR 1.93 (95% CI 1.01-3.69) but not elevated among NAT2 slow acetylators. Women who were NAT2 fast acetylators in the highest quartile for duration of active smoking had an OR of 2.74 (95% CI 1.42-5.27), with a significant test of trend (p=0.005) Conclusion: Active smoking was associated with an increase in breast cancer risk among postmenopausal women and the effect may be differentially modified by NAT2 phenotype. was also a suggestion of an association between passive smoking and increased risk of breast cancer

Keywords:

N-acetyltransferase 2 , passive smoker , active smoker , breast cancer