Abstract
BACKGROUND AND AIM: Benzo[a]pyrene (BaP) is an endocrine-disrupting pollutant formed during incomplete combustion of organic materials. It has been recognized as a reproductive toxicant, however epidemiological evidence of its long-term effect 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 5,222 incident BC cases and 5,222 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. KEYWORDS: airborne benzo[a]pyrene, breast cancer, residential history, menopausal transition, hormone receptor status, differentiation grade
Highlights
Benzo[a]pyrene (BaP) is an endocrine-disrupting pollutant formed during incomplete combustion of organic materials
We provide evidence of increased risk of breast cancer (BC) associated with cumulative BaP exposure, which varied according to menopausal status, hormone receptor status, and grade of differentiation of BC
We considered two adjusted models to account for known BC risk factors and other factors that could potentially confound the association between BaP exposure and BC
Summary
Benzo[a]pyrene (BaP) is an endocrine-disrupting pollutant formed during incomplete combustion of organic materials. BaP air pollution is a major public health problem in areas where domestic coal and wood-burning is frequent. In these areas, BaP emissions have increased in the last decade due to increased emissions from household combustion of biomass (Guerreiro et al, 2014). Industrial sources of BaP include coal liquefaction, coal gasification, coke production, coke ovens, coal-tar distillation, roofing and paving, wood impregnation/preservation with creosote, aluminum production, carbon-electrode manufacture, chim ney sweeping, and power plants, with the highest levels of exposure to PAHs (up to 100 μg/m3) observed in aluminum production (IARC Working Groups, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
