Work and Female Breast Cancer: The State of the Evidence, 2002-2017.

The authors undertook a scoping review to assess the literature from 2002 to 2017 on the relationship between occupation and female breast cancer. Case-control, cohort, and meta-analytic studies suggest that women working as flight attendants, in medical professions, some production positions, sales and retail, and scientific technical staff are likely to have elevated risk of breast cancer. In addition, occupational exposures to night-shift work, ionizing radiation, some chemicals, job stress, and sedentary work may increase risk of breast cancer. Occupational physical activity appears to decrease risk. Workplace exposures to passive smoke and occupational exposure to nonionizing radiation do not appear to affect breast cancer risk. Some studies of occupational categories and workplace exposures indicate that risk may be modified by duration of exposure, timing of exposure, dose, hormone-receptor subtypes, and menopausal status at diagnosis. The compelling data from this review reveal a substantial need for further research on occupation and breast cancer.

Work and Breast Cancer: Recommendations to Address Research Needs.

A review of case-control, cohort, and meta-analytic studies on breast cancer, occupation, and work-related exposures from 2002 to 2017 revealed significant methodological limitations in the current literature. As part of our review, we tabulated the demographic and life history data, breast cancer risk factors, occupational history, and exposure estimates collected and analyzed in each study. Opportunities exist for future research to explore occupation and breast cancer more rigorously and with greater nuance by gathering specific data on age at diagnosis, menopausal status, tumor characteristics, demographics, breast cancer risk factors, and occupational histories, work roles and settings, and exposures. Inclusion of workers in the planning and implementation of research on their occupational risks and exposures is one effective way to refine research questions and ensure research is relevant to workers' needs and concerns.

State of the evidence 2017: an update on the connection between breast cancer and the environment.

BACKGROUND: In this review, we examine the continually expanding and increasingly compelling data linking radiation and various chemicals in our environment to the current high incidence of breast cancer. Singly and in combination, these toxicants may have contributed significantly to the increasing rates of breast cancer observed over the past several decades. Exposures early in development from gestation through adolescence and early adulthood are particularly of concern as they re-shape the program of genetic, epigenetic and physiological processes in the developing mammary system, leading to an increased risk for developing breast cancer. In the 8 years since we last published a comprehensive review of the relevant literature, hundreds of new papers have appeared supporting this link, and in this update, the evidence on this topic is more extensive and of better quality than that previously available. CONCLUSION: Increasing evidence from epidemiological studies, as well as a better understanding of mechanisms linking toxicants with development of breast cancer, all reinforce the conclusion that exposures to these substances - many of which are found in common, everyday products and byproducts - may lead to increased risk of developing breast cancer. Moving forward, attention to methodological limitations, especially in relevant epidemiological and animal models, will need to be addressed to allow clearer and more direct connections to be evaluated.

Environmental exposures, breast development and cancer risk: Through the looking glass of breast cancer prevention.

This review summarizes the report entitled: Breast Cancer and the Environment: Prioritizing Prevention, highlights research gaps and the importance of focusing on early life exposures for breast development and breast cancer risk.

Food packaging and bisphenol A and bis(2-ethyhexyl) phthalate exposure: findings from a dietary intervention.

BACKGROUND: Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) are high-production-volume chemicals used in plastics and resins for food packaging. They have been associated with endocrine disruption in animals and in some human studies. Human exposure sources have been estimated, but the relative contribution of dietary exposure to total intake has not been studied empirically. OBJECTIVES: To evaluate the contribution of food packaging to exposure, we measured urinary BPA and phthalate metabolites before, during, and after a "fresh foods" dietary intervention. METHODS: We selected 20 participants in five families based on self-reported use of canned and packaged foods. Participants ate their usual diet, followed by 3 days of "fresh foods" that were not canned or packaged in plastic, and then returned to their usual diet. We collected evening urine samples over 8 days in January 2010 and composited them into preintervention, during intervention, and postintervention samples. We used mixed-effects models for repeated measures and Wilcoxon signed-rank tests to assess change in urinary levels across time. RESULTS: Urine levels of BPA and DEHP metabolites decreased significantly during the fresh foods intervention [e.g., BPA geometric mean (GM), 3.7 ng/mL preintervention vs. 1.2 ng/mL during intervention; mono-(2-ethyl-5-hydroxy hexyl) phthalate GM, 57 ng/mL vs. 25 ng/mL]. The intervention reduced GM concentrations of BPA by 66% and DEHP metabolites by 53-56%. Maxima were reduced by 76% for BPA and 93-96% for DEHP metabolites. CONCLUSIONS: BPA and DEHP exposures were substantially reduced when participants' diets were restricted to food with limited packaging.

State of the evidence: the connection between breast cancer and the environment.

A substantial body of scientific evidence indicates that exposures to common chemicals and radiation, alone and in combination, are contributing to the increase in breast cancer incidence observed over the past several decades. Key recurring themes in the growing scientific literature on breast cancer and environmental risk factors are: (a) the importance of understanding the effects of mixtures and interactions between various chemicals, radiation and other risk factors for the disease; and (b) the increasing evidence that timing of exposures matters, with exposures during early periods of development being particularly critical to later risk of developing breast cancer. A review of the scientific literature shows several classes of environmental factors have been implicated in an increased risk for breast cancer, including hormones and endocrine-disrupting compounds, organic chemicals and by-products of industrial and vehicular combustion, and both ionizing and non-ionizing radiation.

Policy and research recommendations emerging from the scientific evidence connecting environmental factors and breast cancer.

A substantial body of evidence links environmental exposures to increases in breast cancer incidence over the past decades. State and federal legislative initiatives that could help prevent breast cancer include: federal standards to achieve consistency in radiation-emitting medical and dental equipment; improved state quality assurance standards for radiation-emitting equipment; federal and state exposure limits for electromagnetic radiation; an overhaul of the federal Toxic Substances Control Act to reduce unsafe chemical exposures; strengthened premarket health and safety testing and regulation of pesticides; a federal ban on the manufacture, distribution and sale of consumer products containing bisphenol A and phthalates; and strengthened oversight and regulation of the cosmetics industry. We recommend public and private investment in research on low dose exposures, mixtures, and the timing of chemical exposures, as well as the development of health tracking and biomonitoring programs designed to link data from pollution surveillance systems with disease registries.