Chemicals and Breast Cancer: Building on National Initiatives for Chemical Safety Screening
Understanding how exposure to chemicals in the environment may raise the risk of breast cancer could offer clues to preventing the disease. Currently, the vast majority of chemicals found in homes, consumer products, and the environment have not been safety-tested. For those chemicals that are tested, most of the methods used are not designed to detect chemical effects specific to breast cancer, and they are typically too time- and resource-intensive to screen the tens of thousands of chemicals already on the market. Improving chemical testing methods was a primary research recommendation in the recent report from the Institute of Medicine "Breast Cancer and the Environment: A Life Course Approach."
To increase the relevance of chemical testing to breast cancer, we will develop new screening methods, adapting cell-based (in vitro) chemical tests for use in breast cells and developing new assays, such as those for the mammary-cell specific enzymes involved in estrogen production. By conducting the new tests using animal mammary carcinogens, as well as chemicals that do not cause cancer in animal models, we aim to identify the assays that best predict which chemicals might contribute to the disease.
Results will improve the ability to screen large numbers of chemicals as well as chemical mixtures, such as those in consumer products, house dust, drinking water, and air. The new screening tools could inform the design of safer chemicals (green chemistry), enable manufacturers to select better materials, help regulatory agencies identify chemicals of concern, and contribute to the understanding of environmental factors that contribute to breast cancer risk.
This project is a collaboration between scientists at Silent Spring Institute , University of California-Berkeley, Lawrence Berkeley National Laboratory, and the US Environmental Protection Agency National Center for Computational Toxicology. An Advisory Council consisting of members of the breast cancer advocacy community provides input to the project and assists with disseminating research findings to policymakers and affected communities.
The project is funded by a 3-year grant from the California Breast Cancer Research Program.
It builds on major new initiatives at the US Environmental Protection Agency (ToxCast) and the National Toxicology Program (Tox21), both of which are developing rapid chemical screening methods to fill current gaps in chemical safety evaluation. The project would be strengthened by additional funding to increase the number of chemicals that can be tested. Testing more chemicals would increase the project's statistical power to discriminate between the breast
carcinogens and other chemicals.