Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States.
Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Cancer Epidemiol. 2014 Aug;38(4):376-81. doi: 10.1016/j.canep.2014.05.007. Epub 2014 Jun 12.
Tobacco use has been implicated in the etiology of a large number of cancers, and there exists substantial biological plausibility that it could also be involved in breast carcinogenesis. Despite this, epidemiological evidence to date is inconsistent. The aim of this study was to investigate the role of active smoking and the risk of incident, invasive breast cancer using a prospective cohort of women from the Canadian Study of Diet, Lifestyle and Health.
Using a case-cohort design, an age-stratified subcohort of 3314 women was created from 39,532 female participants who returned completed self-administered lifestyle and dietary questionnaires at baseline. A total of 1096 breast cancer cases were identified in the entire cohort (including 141 cases from the subcohort) by linkage to the Canadian Cancer Registry. Cox regression models were used to estimate hazard ratios for the association between the different smoking exposures and the risk of breast cancer, using a modification for the case-cohort design.
After carefully considering early-life exposures and potential confounders, we found no association between any smoking exposure and risk of breast cancer in this study (Hazard ratio=1.00, 95% confidence interval=0.87-1.17 for ever vs never smokers).
Although these results cannot rule out an association between smoking and breast cancer, they do agree with the current literature suggesting that, if an association does exist, it is relatively weak.
吸烟与大量癌症的病因有关，而且有大量生物学上的合理性表明它也可能参与乳腺癌的发生。尽管如此，迄今为止的流行病学证据并不一致。本研究的目的是使用来自加拿大饮食、生活方式和健康研究的前瞻性队列研究来调查主动吸烟与浸润性乳腺癌发病风险之间的关系。
使用病例-队列设计，从 39532 名返回完整自我管理生活方式和饮食问卷的女性参与者中，按年龄分层创建了 3314 名女性的年龄分层亚队列。通过与加拿大癌症登记处的链接，在整个队列中（包括亚队列中的 141 例）确定了 1096 例乳腺癌病例。使用病例-队列设计的修正，Cox 回归模型来估计不同吸烟暴露与乳腺癌风险之间的关联的风险比。
在仔细考虑了早期生活暴露和潜在混杂因素后，我们在这项研究中没有发现任何吸烟暴露与乳腺癌风险之间的关联（风险比=1.00，95%置信区间=0.87-1.17，从不吸烟者与曾经吸烟者相比）。
尽管这些结果不能排除吸烟与乳腺癌之间的关联，但它们与当前的文献一致，表明如果确实存在关联，其关联也相对较弱。
