Danjou Aurélie M N, Fervers Béatrice, Boutron-Ruault Marie-Christine, Philip Thierry, Clavel-Chapelon Françoise, Dossus Laure
Breast Cancer Res. 2015 Mar 17;17:39. doi: 10.1186/s13058-015-0536-9.
Dioxins are environmental and persistent pollutants mostly emitted from combustion facilities (e.g. waste incinerators, metal and cement industries). Known to be endocrine disrupting chemicals, dioxins are suspected to increase breast cancer (BC) risk. Although diet is considered the primary source of dioxin exposure, no previous study has been published on dietary dioxin exposure in relation to BC risk. We aimed to assess dietary dioxin exposure among women from the E3N cohort and estimate BC risk associated with this exposure.
The study included 63,830 women from the E3N cohort who completed a diet history questionnaire (DHQ) in 1993 and were followed until 2008. Dietary dioxin exposure was estimated by combining consumption data from the E3N DHQ and food dioxin contamination data from a French national monitoring program. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox models adjusted for BC risk factors.
Mean dietary dioxin exposure was estimated at 1.3 ± 0.4 pg/kg body weight (BW)/day. A 0.4 pg/kg BW/d increase in dioxin intake was not associated with overall BC risk (HR = 1.00; 95% CI: 0.96, 1.05). A significant decrease in risk of estrogen receptor negative (ER-)/progesterone receptor negative (PR-) tumors was observed among post-menopausal women in the upper quartile of estimated dioxin intake (HR for Q4 vs. Q1: 0.65; 95% CI: 0.45, 0.96; P for trend across quartiles = 0.0463).
Overall, no association between estimated dietary dioxin exposure and BC risk was found among E3N women. Further studies should include both dietary and environmental exposures to determine whether low-dose dioxin exposure is associated with BC risk.
二噁英是环境持久性污染物，主要由燃烧设施（如垃圾焚烧炉、金属和水泥行业）排放。二噁英被认为是内分泌干扰化学物质，怀疑会增加患乳腺癌（BC）的风险。尽管饮食被认为是二噁英暴露的主要来源，但此前尚无关于饮食中二噁英暴露与BC风险关系的研究发表。我们旨在评估E3N队列中女性的饮食二噁英暴露情况，并估计与此暴露相关的BC风险。
该研究纳入了E3N队列中的63830名女性，她们于1993年完成了饮食史问卷（DHQ），并随访至2008年。通过结合E3N DHQ的消费数据和法国国家监测计划的食品二噁英污染数据来估计饮食二噁英暴露。通过针对BC风险因素进行调整的Cox模型估计风险比（HR）和95%置信区间（CI）。
估计平均饮食二噁英暴露量为1.3±0.4 pg/kg体重（BW）/天。二噁英摄入量每增加0.4 pg/kg BW/d与总体BC风险无关（HR = 1.00；95% CI：0.96，1.05）。在估计二噁英摄入量处于上四分位数的绝经后女性中，雌激素受体阴性（ER-）/孕激素受体阴性（PR-）肿瘤的风险显著降低（Q4与Q1的HR：0.65；95% CI：0.45，0.96；四分位数间趋势的P = 0.0463）。
总体而言，在E3N女性中未发现估计的饮食二噁英暴露与BC风险之间存在关联。进一步的研究应包括饮食和环境暴露，以确定低剂量二噁英暴露是否与BC风险相关。
