Background

Although the genetic and hormonal risk factors of breast cancer are well identified, they cannot fully explain the occurrence of all cases. Epidemiological and experimental studies have suggested that exposure to environmental pollutants, especially those with potential estrogenic properties, as polychlorinated biphenyls (PCBs) may have a role in breast cancer development. Being the most abundantly detected in human tissues and in the environment, congener 153 (PCB153) is widely used in epidemiological studies as indicator for total PCBs exposure.

Objectives

We aimed to estimate the association between cumulative atmospheric exposure to PCB153 and breast cancer risk.

Methods

We conducted a case-control study of 5222 cases and 5222 matched controls nested within the French E3N cohort from 1990 to 2011. Annual atmospheric PCB153 concentrations were simulated with the deterministic chemistry-transport model (CHIMERE) and were assigned to women using their geocoded residential history. Their cumulative PCB153 exposure was calculated for each woman from their cohort inclusion to their index date. Breast cancer odds ratios (ORs) associated with cumulative PCB153 exposure and their 95% confidence intervals (95% CIs) were estimated using multivariate conditional logistic regression models.

Results

Overall, our results showed a statistically significant linear increase in breast cancer risk related to cumulative atmospheric exposure to PCB153 as a continuous variable (adjusted OR = 1.19; 95% CI: 1.08–1.31, for an increment of one standard deviation among controls (55 pg/m³)). Among women who became postmenopausal during follow-up, the association remained statistically significant (adjusted OR = 1.23; 95% CI: 1.09–1.39). In analyses by hormone receptors status, the positive association remained significant only for ER-positive breast cancer (adjusted OR = 1.18; 95% CI: 1.05–1.33).

Discussion

This study is the first to have estimated the impact of atmospheric exposure to PCB153 on breast cancer risk. Our results showed a statistically significant increase in breast cancer risk, which may be limited to ER-positive breast cancer. These results warrant confirmation in further independent studies but raise the possibility that exposure to PCB153 increase breast cancer risk.

中文翻译：

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1990年至2011年在法国E3N队列中进行的一项病例对照研究表明，长期在大气中接触PCB153和乳腺癌的风险

背景

尽管乳腺癌的遗传和激素危险因素已被很好地识别，但它们不能完全解释所有病例的发生。流行病学和实验研究表明，暴露于环境污染物中，尤其是具有潜在雌激素特性的污染物，因为多氯联苯（PCB）可能在乳腺癌的发展中起作用。同源物153（PCB153）是人体组织和环境中检测最丰富的物质，在流行病学研究中被广泛用作PCB暴露总量的指标。

目标

我们旨在评估PCB153累积的大气暴露与乳腺癌风险之间的关联。

方法

我们从1990年至2011年对法国E3N队列中嵌套的5222例病例和5222匹配的对照者进行了病例对照研究。使用确定性化学迁移模型（CHIMERE）模拟了年大气中PCB153的浓度，并使用其地理编码的居住区将其分配给了女性历史。计算每个女性从队列纳入到索引日期的累积PCB153暴露量。使用多元条件对数回归模型估算与累积PCB153暴露相关的乳腺癌比值比（OR）及其95％置信区间（95％CI）。

结果

总体而言，我们的结果显示，与连续暴露于PCB153的大气累积暴露相关的乳腺癌风险的统计学显着线性增加（调整后的OR = 1.19； 95％CI：1.08-1.31，对照组之间的标准差增加了55） pg / m ³））。在随访期间绝经后的妇女中，该关联仍具有统计学意义（校正后OR = 1.23； 95％CI：1.09–1.39）。在按激素受体状态进行的分析中，仅对ER阳性乳腺癌呈正相关（校正OR = 1.18； 95％CI：1.05-1.33）。

讨论区

这项研究是第一个估计大气中PCB153暴露对乳腺癌风险的影响的研究。我们的结果表明，乳腺癌风险有统计学上的显着增加，这可能仅限于ER阳性乳腺癌。这些结果值得进一步的独立研究证实，但增加了接触P​​CB153的可能性，增加了患乳腺癌的风险。