Background

Benzo[a]pyrene (BaP) is an endocrine-disrupting pollutant formed during incomplete combustion of organic materials. It has been recognized as a reproductive and developmental toxicant, however epidemiological evidence of the long-term effect of ambient air BaP on breast cancer (BC) is limited. Thus we evaluated associations between ambient air BaP exposure and risk of BC, overall and according to menopausal status and molecular subtypes (estrogen receptor negative/positive (ER−/ER+) and progesterone receptor negative/positive (PR−/PR+)), stage and grade of differentiation of BC in the French E3N cohort study.

Methods

Within a nested case-control study of 5222 incident BC cases and 5222 matched controls, annual BaP exposure was estimated using a chemistry-transport model (CHIMERE) and was assigned to the geocoded residential addresses of participants for each year during the 1990–2011 follow-up period. Multivariable conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Overall, cumulative airborne BaP exposure was significantly associated with the overall risk of BC, for each 1 interquartile range (IQR) increase in the concentration levels of BaP (1.42 ng/m³), the OR = 1.15 (95% CI: 1.04–1.27). However, by menopausal status, the significant positive association remained only in women who underwent menopausal transition (i.e. premenopausal women at inclusion who became postmenopausal at diagnosis), OR per 1 IQR = 1.20 (95% CI: 1.03–1.40). By hormone receptor status, positive associations were observed for ER+, PR + and ER + PR + BC, with ORs = 1.17 (95% CI: 1.04–1.32), 1.16 (95% CI: 1.01–1.33), and 1.17 (95% CI: 1.01–1.36) per 1 IQR, respectively. There was also a borderline positive association between BaP and grade 3 BC (OR per 1 IQR = 1.15 (95% CI: 0.99–1.34).

Conclusions

We provide evidence of increased risk of BC associated with cumulative BaP exposure, which varied according to menopausal status, hormone receptor status, and grade of differentiation of BC. Our results add further epidemiological evidence to the previous experimental studies suggesting the adverse effects of BaP.

中文翻译：

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长期暴露于苯并[a]（（BaP）空气污染相关的乳腺癌风险：来自法国E3N队列研究的证据

背景

苯并[a] py（BaP）是破坏有机物的过程中形成的内分泌干扰污染物。它被认为是生殖和发育毒物，但是流行病学证据表明环境空气BaP对乳腺癌（BC）的长期影响是有限的。因此，我们根据总体绝经状态和分子亚型（雌激素受体阴性/阳性（ER- / ER +）和孕激素受体阴性/阳性（PR- / PR +）），阶段评估了环境空气中BaP暴露与BC风险之间的关联。法国E3N队列研究中BC的分化程度和分化程度。

方法

在一项针对5222例BC病例和5222例相匹配的对照的嵌套病例对照研究中，使用化学迁移模型（CHIMERE）估算了每年的BaP暴露量，并将其分配给1990-2011年期间每年参与者的地理编码住址上升期。多变量条件对数回归模型用于估计比值比（OR）和95％置信区间（CI）。

结果

总体而言，累积的空气中BaP暴露量与BC的总体风险显着相关，BaP浓度水平每升高1个四分位数范围（IQR）（1.42 ng / m ³），OR = 1.15（95％CI：1.04– 1.27）。然而，根据绝经状态，只有正经历绝经过渡的女性（即，在诊断时就进入绝经的绝经前女性）或每1 IQR = 1.20（95％CI：1.03-1.40）才具有显着的正相关性。根据激素受体状态，观察到ER +，PR +和ER + PR + BC呈正相关，OR分别为1.17（95％CI：1.04-1.32），1.16（95％CI：1.01-1.33）和1.17（95） ％CI：每1 IQR分别为1.01-1.36）。BaP和BC 3级之间也存在临界的正相关（每1 IQR的OR = 1.15（95％CI：0.99–1.34））。

结论

我们提供了与累积BaP暴露相关的BC风险增加的证据，BaP暴露随绝经状态，激素受体状态和BC分化程度而异。我们的结果为以前的实验研究提供了进一步的流行病学证据，表明BaP的不良反应。