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Janet Gray, Ph.D.
Janet Gray, Ph.D.

As author of our 2008 and 2010 State of the Evidence reports, Dr. Gray drives the science behind all our work.

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The Biology of Breast Cancer

To understand how to reduce breast cancer risk, we first need to look at the biology of breast development, and of how that development can be disrupted. Though scientists still have unanswered questions related to breast cancer causation, we do understand a great deal about the stages of breast development, the impact of endocrine-disrupting compounds and carcinogens, and the interplay between genetics and the environment. This section examines the development of the breast from prenatal stages through menopause, provides an overview of the endocrine system, and outlines the varying breast cancer subtypes.

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    Breast Cancer Subtypes

    Multiple subtypes occur at different rates in different groups and have varied long-term survival rates.

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    The Endocrine System

    Regulates body growth and directs development of breasts.

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    Endocrine-disrupting Compounds

    Chemicals in products can mimick natural hormones & affect the body's development.

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    Genetic, Epigenetic and Tissue Organizational Effects

    Environmental factors may impact whether or not gene mutations express themselves as cancer.

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    The Human Breast

    Breast development occurs at four primary stages, and exposure to certain chemicals can disrupt the process.

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  • Breast Cancer Statistics

    Today a U.S. woman’s lifetime risk of breast cancer is 1 in 8.

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