Silent Spring scientists are mapping the molecular pathways that lead to the development of breast cancer as part of an international effort to improve chemical safety testing.
test tubes

The Adverse Outcome Pathways (AOPs) project maps the molecular changes that occur in the body from the time a person is exposed to a chemical all the way through to the formation of a tumor. The project is part of a broader international effort launched by the Organization for Economic Cooperation and Development (OECD) to learn how chemicals affect human health. 

An AOP is an analytical framework that describes a series of molecular changes in the body. The changes are linked together as part of a sequence of events that eventually lead to an adverse health or toxicological effect. AOPs play an important role in chemical risk assessment.

Our project will fill an important gap in the AOPs program. Initially, the program did not include breast cancer and women's health. To fill that gap, Silent Spring has taken a leading role in this area. We are developing AOPs for breast cancer for three different types of exposures: 1) ionizing radiation, 2) hormone replacement therapy, and 3) early disruption of mammary gland development by endocrine disrupting compounds.