Environmental oestrogens and breast cancer: long-term low-dose effects of mixtures of various chemical combinations

• Published in: Journal of epidemiology and community health (1979) 2013-03, Vol.67 (3), p.203-205
• Main Authors: Darbre, Philippa D, Fernandez, Mariana F
• Format: Article
• Language: English
• Subjects: Adipose tissues; Avoidable Deaths; Biomarkers; Bisphenol A; Breast cancer; Breast Neoplasms - chemically induced; Breast Neoplasms - prevention & control; Cancer: Breast; Cancer: Hormones; Chemical hazards; Chemicals; Community health; Contraceptives; Control Of Diseases; Editorial; Environmental assessment; Environmental Exposure - prevention & control; Environmental Pollutants - adverse effects; Esters; Estrogens; Estrogens - adverse effects; Estrogens - biosynthesis; Female; Green chemistry; Health risk assessment; Hormone replacement therapy; Hormones; Humans; Menopause; Organic compounds; PCB; Phenols; Physiology; Pollutants; Polychlorinated biphenyls; Pregnancy; Risk Factors; Studies; Tissue samples; Toxicology
• ISSN: 0143-005X; 1470-2738
• DOI: 10.1136/jech-2012-201362

The incidence of breast cancer has risen worldwide to unprecedented levels in recent decades, making it now the major cancer of women in many parts of the world. 1 Although diet, alcohol, radiation and inherited loss of BRCA1/2 genes have all been associated with increased incidence, the main identified risk factors are life exposure to hormones including physiological variations associated with puberty/pregnancy/menopause, 1 personal choice of use of hormonal contraceptives 2 and/or hormone replacement therapy. 3-6 On this basis, exposure of the human breast to the many environmental pollutant chemicals capable of mimicking or interfering with oestrogen action 7 should also be of concern. 8 Hundreds of such environmental chemicals have now been measured in human breast tissue from a range of dietary and domestic exposure sources 7 9 including persistent organochlorine pollutants (POPs), 10 polybrominated diphenylethers and polybromobiphenyls, 11 polychlorinated biphenyls, 12 dioxins, 13 alkyl phenols, 14 bisphenol-A and chlorinated derivatives, 15 as well as other less lipophilic compounds such as parabens (alkyl esters of p-hydroxybenzoic acid), 16 but studies investigating any association between raised levels of such compounds and the development of breast cancer remain inconclusive. 7-16 However, the functionality of these chemicals has continued to be assessed on the basis of individual chemicals rather than the environmental reality of long-term low-dose exposure to complex mixtures.