Background: Most studies on endocrine-disrupting chemicals and breast cancer have focused on single compounds and have produced inconclusive findings.
Objectives: We assessed the combined estrogenic effects of mixtures of xenoestrogens in serum and their relationship to breast cancer risk.
Methods: A total of 186 incident pretreatment breast cancer cases and 196 frequency-matched controls were randomly sampled from a large population-based multicase–control study in Spain. The total effective xenoestrogen burden attributable to organohalogenated xenoestrogens (TEXB-α) and endogenous hormones and more polar xenoestrogens (TEXB-β) was determined in serum samples using high-performance liquid chromatography and E-Screen bioassay. Odds ratios for breast cancer comparing tertiles of serum TEXB-α and TEXB-β were estimated using logistic models, and smooth risk trends were obtained using spline models.
Results: Cases had higher geometric mean TEXB-α and TEXB-β levels (8.32 and 9.94 Eeq pM/mL, respectively) than controls (2.99 and 5.96 Eeq pM/mL, respectively). The fully adjusted odds ratios for breast cancer (95% confidence intervals) comparing the second and third tertiles of TEXB-α with the first tertile were 1.77 (0.76, 4.10) and 3.45 (1.50, 7.97), respectively, and those for TEXB-β were 2.35 (1.10, 5.03) and 4.01 (1.88, 8.56), respectively. A steady increase in risk was evident across all detected TEXB-α levels and a sigmoidal trend was observed for TEXB-β. Individual xenoestrogens showed weak and opposing associations with breast cancer risk.
Conclusions: This is the first study to show a strong positive association between serum total xenoestrogen burden and breast cancer risk, highlighting the importance of evaluating xenoestrogen mixtures, rather than single compounds, when studying hormone-related cancers.
1Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; 2Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain; 3Biosanitary Institute of Granada (ibs.GRANADA), University of Granada, Granada, Spain; 4Center for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; 5Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; 6Pompeu Fabra University (UPF), Barcelona, Spain; 7USA-Spain Fulbright Commission for Cultural, Educational and Scientific Exchange, Madrid, Spain; 8Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; 9Division of Epidemiology and Computational Biology, School of Medicine, University of Cantabria, Santander, Spain; 10Public Health Institute of Navarra, Pamplona, Spain; 11Medicine Department, Autonomous University of Barcelona, Barcelona, Spain; 12Medical Oncology Department, Hospital del Mar, Barcelona, Spain
Recommended Citation:
Roberto Pastor-Barriuso,1,2* Mariana F. Fernández,et al. Total Effective Xenoestrogen Burden in Serum Samples and Risk for Breast Cancer in a Population-Based Multicase–Control Study in Spain[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 10):1575