Prenatal Exposure to Polybrominated Diphenyl Ethers (PBDEs) Flame Retardants and Breast Tissue Composition among Adolescents Girls

Abstract

Exposure to endocrine-disrupting chemicals including PBDEs during the prenatal period may affect breast development and composition and the risk of developing breast cancer in adulthood. We examined the association between prenatal exposure to PBDEs and breast tissue composition in adolescent girls. We used data from the Columbia’s Breast Cancer and the Environment Research Project (BCERP), part of the Columbia Center for Children's Environmental Health birth cohort. Prenatal PBDE concentrations were measured in cord blood from African-American or Dominican neonates, born between 1998 and 2006 (prior to PBDE phase out). After longitudinal follow-up, breast tissue composition was measured using optical spectroscopy (OS) in adolescent girls between 2016 and 2020. OS is a non-invasive device that uses visible and near infrared light to provide a broad compositional view of the breast by capturing variation in the amount of water, lipid, oxy-hemoglobin, deoxy-hemoglobin (HbO2), and collagen, and cellular and connective tissue density. Spectral data was reduced using principal component analysis and principal component (PC) scores were generated for each girl (averaged over both breasts). Associations between lipid-adjusted PBDE concentrations (ln) and PC scores were evaluated using linear regression. The analysis included 94 daughters (ages 12.6 to 19.9 years, median=16.9 years). Five PCs explained 99.9% of the variation in OS data. When examining PBDE as continuous, PC2 scores were lower on average for girls with higher prenatal concentrations of BDE-47 (overall sample geometric mean = 11.82 ng/g lipid; βBDE-47 = -0.05, 95% CI:-0.09, -0.005) after adjusting for age and body mass index. Results were consistent when examining PBDEs using median cut-points. PC2 covered 3.8% of the spectral variations and was related to overall lower HbO2 and higher water. Associations were attenuated in fully adjusted models. We found evidence suggesting that prenatal exposure to PBDEs may be associated with breast tissue composition in adolescent girls.