Epidemiology, Outcomes & Evaluation Research, Regional Cancer Program of the Sudbury Regional Hospital, Sudbury, Ontario, Canada P3E 5J1.
Cancer Epidemiol. 2010 Apr;34(2):142-9. doi: 10.1016/j.canep.2010.02.001. Epub 2010 Mar 1.
The relationship between smoking and breast cancer remains controversial. The study aim was to assess the relationship of passive and active smoking to breast cancer risk by N-acetyltransferase 2 (NAT2) phenotype, using a comprehensive assessment of both passive and active smoking.
We undertook a population-based case-control study in Northeastern Ontario, Canada of 347 women diagnosed (2002-2004) with breast cancer and 775 population-based controls. The mailed study package included a questionnaire requesting information about established 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).
These findings suggest that passive and active smoking may be related to breast cancer, and the effect may be differentially modified by NAT2 phenotype. Further research into the genetic modification of a breast cancer-smoking relationship may help to reconcile earlier discrepant findings.
吸烟与乳腺癌之间的关系仍存在争议。本研究旨在通过乙酰转移酶 2（NAT2）表型，综合评估被动吸烟和主动吸烟，评估被动吸烟和主动吸烟与乳腺癌风险之间的关系。
我们在加拿大安大略省东北部进行了一项基于人群的病例对照研究，纳入了 347 名 2002-2004 年间确诊的乳腺癌患者（病例组）和 775 名基于人群的对照组。邮寄的研究包包括一份问卷，要求提供有关已确定的乳腺癌危险因素、被动吸烟和主动吸烟的信息，以及进行基因分析的口腔拭子。
在从未主动吸烟的女性中，较长时间的被动吸烟与乳腺癌风险增加相关（比值比（OR）1.86，95%置信区间（95%CI）1.01-3.44）（趋势检验（p=0.07））；对于 NAT2 慢乙酰化者，风险更高（OR 2.76，95%CI 1.16-6.59）（且在极度慢乙酰化者中最高），但对于 NAT2 快乙酰化者则没有升高（OR 1.17，95%CI 0.42-3.23）。对于吸烟超过 20 包年的主动吸烟者，OR 为 1.34（95%CI 0.92-1.96）；在 NAT2 快乙酰化者中，风险更高（OR 1.93，95%CI 1.01-3.69），但在 NAT2 慢乙酰化者中没有升高。在吸烟持续时间最高四分位数的 NAT2 快乙酰化者中，OR 为 2.74（95%CI 1.42-5.27），趋势检验具有显著意义（p=0.005）。
这些发现表明，被动吸烟和主动吸烟可能与乳腺癌有关，且这种影响可能因 NAT2 表型而异。进一步研究乳腺癌与吸烟之间的遗传修饰关系可能有助于调和先前存在的不一致发现。
