1. Affiliations of authors: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (JLB, MC, ASR, XL); Department of Preventive Medicine, University of Southern California, Los Angeles, CA (RWH, BL, DCT, ATD); Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (MS, SAS); International Epidemiology Institute, Rockville, MD (JDB); Departme