1. From the Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, TX (SM); the US Department of Agriculture, Agricultural Research Service, Beltsville, MD (DJB, BAC, and WSC); the Information Management Services Inc, Silver Spring, MD (CG); the Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Institutes of Health, Bethesda, MD (PRT