Author Contributions: Dr King had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Walsh, Coats, Swisher, King.
Acquisition of data: Walsh, Casadei, Coats, Swisher, Stray, Higgins, Roach, Mandell, Ciernikova, Foretova, Soucek, King.
Analysis and interpretation of data: Walsh, Casadei, Coats, Swisher, Higgins, Lee, Ciernikova, Foretova, King.
Drafting of the manuscript: Walsh, Casadei, Coats, Swisher, Ciernikova, Foretova, Soucek, King.
Critical revision of the manuscript for important intellectual content: Walsh, Casadei, Coats, Swisher, Stray, Higgins, Roach, Mandell, Lee, Ciernikova, Foretova, Soucek, King.
Statistical analysis: Lee, King.
Obtained funding: Ciernikova, Foretova, Soucek, King.
Administrative, technical, or material support: Walsh, Casadei, Coats, Swisher, Stray, Higgins, Roach, Mandell, King.
Study supervision: Walsh, King.
Drs Walsh and Casadei and Ms Coats contributed equally to this study.
Financial Disclosures: None reported.
Funding/Support: This study was supported by grants from the National Institutes of Health (R01 ES13160), the European program for Co-Operation in Scientific and Technical (COST) Research and the Ministry of Education, Youth, and Sports of the Czech Republic (OCB20.001), the Ministry of Health of the Czech Republic (MZO00209805), and the Breast Cancer Research Foundation. Dr King is the Disney Foundation–American Cancer Society Research Professor.
Role of the Sponsors: Neither the National Institutes of Health nor the Breast Cancer Research Foundation had any role in the design and conduct of the study; the collection, management, analysis, or interpretation of the data; or the preparation, review, or approval of the manuscript.
Acknowledgment: We thank the families for their enthusiastic participation in this study. For technical assistance, counseling assistance, and advice, we thank Melissa Wollan, BS, Melissa Villanueva, BS, Kirstin Wiederholt, BS, Ksenia Peters Koon, MS, and Avraham Shaag, PhD, Departments of Medicine and Genome Sciences, University of Washington, Seattle, Julia Willner, MD, Department of Obstetrics and Gynecology, University of Washington, and Miroslava Lukesova, MS, Hana Pavlu, Veronika Urbankova, and Jitka Kuklova, Department of Cancer Epidemiology and Statistics, Masaryk Memorial Cancer Institute, Brno, Czech Republic. For tumor material from the Prague cohort, we thank Roman Kodet, MD, Department of Pathology, Teaching Hospital Motol, Prague, Czech Republic.