Johnson Kenneth C
Surveillance and Risk Assessment Division, Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, Ottawa, Ontario.
Int J Cancer. 2005 Nov 20;117(4):619-28. doi: 10.1002/ijc.21150.
The aim of the study was to examine the risk of breast cancer associated with passive and active smoking and to explore risk heterogeneity among studies. Nineteen of 20 located published studies of passive smoking and breast cancer risk among women met basic quality criteria. Pooled relative risk estimates for breast cancer were calculated for 1) life-long non-smokers with regular passive exposure to tobacco smoke and 2) women who smoked. They were compared to women categorized as never regularly exposed to tobacco smoke. The pooled risk estimate for breast cancer associated with passive smoking among life-long non-smokers was 1.27 (95% confidence interval (CI), 1.11-1.45). In the subset of 5 studies (all case-control studies) with more complete exposure assessment (quantitative long-term information on the 3 major sources of passive smoke exposure: childhood, adult residential and occupational), the pooled risk estimate for exposed non-smokers was 1.90 (95%CI, 1.53-2.37). For the 14 studies with less complete passive exposure measures the risk was 1.08 (95%CI, 0.99-1.19) overall, 1.16 for 7 case-control and 1.06 for 7 cohort studies, although dose-response results in 3 of 4 Asian cohort studies suggested increased risk. The overall premenopausal breast cancer risk associated with passive smoking among life-long non-smokers was 1.68 (95%CI 1.33-2.12), and 2.19 (95% CI 1.68-2.84) for the 5 of 14 studies with more complete exposure assessment. For women who had smoked the breast cancer risk estimate was 1.46 (95%CI 1.15-1.85) when compared to women with neither active nor regular passive smoke exposure; 2.08 (95% CI 1.44-3.01) for more complete and 1.15 (95% CI 0.92-1.43) for less complete passive exposure assessment. Studies with thorough passive smoking exposure assessment implicate passive and active smoking as risk factors for premenopausal breast cancer. Cohort studies with thorough passive smoking assessment would be helpful and studies exploring biological mechanisms are needed to explain the unexpected similarity of the passive and active risks.
本研究的目的是检验与被动吸烟和主动吸烟相关的乳腺癌风险，并探讨各研究之间风险的异质性。在找到的20项已发表的关于女性被动吸烟与乳腺癌风险的研究中，有19项符合基本质量标准。计算了以下两类人群患乳腺癌的合并相对风险估计值：1）长期被动接触烟草烟雾的终生不吸烟者；2）吸烟女性。将他们与被归类为从未经常接触烟草烟雾的女性进行比较。终生不吸烟者中与被动吸烟相关的乳腺癌合并风险估计值为1.27（95%置信区间（CI），1.11 - 1.45）。在5项（均为病例对照研究）对暴露评估更完整的研究子集中（关于被动吸烟暴露的3个主要来源：儿童期、成年期居住和职业的定量长期信息），暴露的不吸烟者的合并风险估计值为1.90（95%CI，1.53 - 2.37）。对于14项被动暴露测量不太完整的研究，总体风险为1.08（95%CI，0.99 - 1.19），7项病例对照研究为1.16，7项队列研究为1.06，尽管4项亚洲队列研究中有3项的剂量反应结果表明风险增加。终生不吸烟者中与被动吸烟相关的绝经前乳腺癌总体风险为1.68（95%CI 1.33 - 2.12），在14项研究中有5项对暴露评估更完整的研究中为2.19（95%CI 1.68 - 2.84）。与既无主动吸烟也无规律被动吸烟暴露的女性相比，吸烟女性的乳腺癌风险估计值为1.46（95%CI 1.15 - 1.85）；被动暴露评估更完整时为2.08（95%CI 1.44 - 3.01），评估不太完整时为1.15（95%CI 0.92 - 1.43）。对被动吸烟暴露评估全面的研究表明，被动吸烟和主动吸烟是绝经前乳腺癌的风险因素。进行全面被动吸烟评估的队列研究将有所帮助，并且需要开展探索生物学机制的研究来解释被动吸烟和主动吸烟风险意外相似的原因。
