Chronic Exposure to Air Pollution and Breast Cancer Risk: Finding from a Nested Case-Control Study within the French E3N-Générations Cohort
Seance of wednesday 09 april 2025 (Cancer environnement)
DOI number : 10.26299/xtfp-9c30/2025.14.02
Abstract
Breast cancer is the most common cancer in women (66,000 new cases in 2022 in France). While genetic and hormonal factors are well understood, they do not explain all cases. Studies suggest that several environmental pollutants, particularly endocrine disruptors, may play a role, although the results remain inconsistent.
The XENAIR project investigated the link between breast cancer risk and chronic low-dose exposure to 7 atmospheric pollutants, which are endocrine disruptors (dioxins, benzo[a]pyrene (BaP), polychlorinated biphenyls (PCBs), cadmium), and to which the French population is predominantly exposed (particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2)). The study is based on a case-control study nested in the E3N-Générations cohort, including 5,222 cases of breast cancer (1990–2011) and 5,222 matched controls. The use of various complementary methods (Geographic Information System, Land Use Regression and CHIMERE) allowed for the estimation of pollutant concentrations from 1990 to 2011 at the women's residential addresses.
The project results revealed a decrease in exposure for the study participants between 1990 and 2011. However, exposure levels remain well above current WHO health recommendations.
The results showed a significant association with increased exposure to NO2, PM10, PM2.5, BaP, PCB153, and dioxins. The analysis of the combined exposure to the 7 pollutants confirmed the association with breast cancer risk.
This is the first study to analyze the individual effect of these 7 pollutants on breast cancer risk, with a detailed estimation of exposures, considering the participants' residential history over 22 years.
The XENAIR project investigated the link between breast cancer risk and chronic low-dose exposure to 7 atmospheric pollutants, which are endocrine disruptors (dioxins, benzo[a]pyrene (BaP), polychlorinated biphenyls (PCBs), cadmium), and to which the French population is predominantly exposed (particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2)). The study is based on a case-control study nested in the E3N-Générations cohort, including 5,222 cases of breast cancer (1990–2011) and 5,222 matched controls. The use of various complementary methods (Geographic Information System, Land Use Regression and CHIMERE) allowed for the estimation of pollutant concentrations from 1990 to 2011 at the women's residential addresses.
The project results revealed a decrease in exposure for the study participants between 1990 and 2011. However, exposure levels remain well above current WHO health recommendations.
The results showed a significant association with increased exposure to NO2, PM10, PM2.5, BaP, PCB153, and dioxins. The analysis of the combined exposure to the 7 pollutants confirmed the association with breast cancer risk.
This is the first study to analyze the individual effect of these 7 pollutants on breast cancer risk, with a detailed estimation of exposures, considering the participants' residential history over 22 years.