ASPO Abstracts
Urinary metabolites of environmental phenols and breast cancer incidence: the Long Island Breast Cancer Study Project
Category: Molecular Epidemiology & Environment, Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2018
Abstract Body:
Background: Select environmental phenols, compounds used widely in personal care and consumer products, are known endocrine disruptors. However, no epidemiologic studies have objectively examined whether phenols are associated with breast cancer. Purpose: To examine seven urinary phenol biomarkers (2,5-dichlorophenol, benzophenone-3, bisphenol A (BPA), methyl-, propyl-, butyl-paraben, and triclosan) in association with breast cancer, and to examine effect modification by body mass index (BMI) given that adipose tissue is a source of estrogens, and phenols are lipophilic. Methods: Participants were a subsample of women (711 cases and 598 controls) from a population-based study of breast cancer. Urinary phenol biomarkers were measured in spot samples collected on average within three months of a first diagnosis of primary in situ or invasive breast cancer in 1996/1997. We used logistic regression to estimate covariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for creatinine-corrected phenol concentrations. Results: Among all women, the highest (vs lowest) quintiles of methyl- and propyl-paraben were associated with 52% (OR=1.52, 95% CI=1.02-2.27) and 38% (OR=1.38, 95% CI=.93-2.07) increased odds, respectively, of breast cancer. A ln-unit increase in propyl-paraben was associated with a 15% increase (OR=1.15, 95% CI=1.04-1.28) in breast cancer odds among women with BMI<25.0 kg/m2, but not among women with BMI25.0 kg/m2 (OR=.99, 95% CI=.91-1.09) (Pinteraction=0.02). There was a suggestion of effect modification by BMI for methyl-paraben (Pinteraction=0.12) and BPA (Pinteraction=0.11). Ln-transformed continuous concentrations of methyl-paraben positively associated with breast cancer among women with BMI<25.0 kg/m2 (OR=1.15, 95% CI=1.01-1.32), but not among women with BMI25.0 kg/m2 (OR=1.02, 95% CI=.91-1.14). Ln-transformed continuous concentrations of BPA were inversely associated with breast cancer among women with BMI<25.0 kg/m2 (OR=.78, 95% CI=.64-.95), but not among women with BMI25.0 kg/m2 (OR=1.01, 95% CI=.84-1.22). Conclusions: Exposure to select phenols may increase breast cancer risk; however, because of potential for reverse causation in this case-control study, future studies should examine these associations prospectively.
Keywords: Breast cancer; environmental phenols, personal care products, parabens, BPA