Breast cancer remained a hidden disease among women in the United States until the 20th century. It was initially brought into the open with public revelations from individual women, which was followed by the development of support groups and ultimately the formation of political activist groups with various priorities. Those concerned with toxic environmental exposures as a potential cause of breast cancer organized, demonstrated, and lobbied for research funding and eventually became partners in the research that arose from their efforts. One representative example was the Breast Cancer and Environment Research Centers (BCERC) Project (2003-2010), supported by the National Institute of Environmental Health Sciences (NIEHS) and the National Cancer Institute (NCI). The BCERC embedded a Community Outreach and Translational Core into its formal organizational infrastructure to ensure advocate involvement in the standing scientific subcommittees of BCERC, the first project funded by NIEHS and NCI to do so. The formal integration of advocates as partners in scientific studies focused on breast cancer is embedded in a rich history of action on the part of many courageous women. This article describes the historical evolution of breast cancer activism in the United States, which provided a critical foundation for the formation of BCERC. This description is followed by a discussion of BCERC as an example of the transdisciplinary research model, a paradigm that strives for inclusion of multiple stakeholders and increased interaction between scientists from a wide spectrum of disciplines, advocates, and lay audiences in order to more effectively conduct critical research and to translate and disseminate its findings.