Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America, Division of Biostatistics, The University of Texas School of Public Health, Houston, Texas, United States of America.|Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America, Human & Molecular Genetics Program, The University of Texas Graduate School of Biomedical Sciences, Houston, Texas, United States of America.|Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America, Division of Biostatistics, The University of Texas School of Public Health, Houston, Texas, United States of America, Human & Molecular Genetics Program, The University of Texas Graduate School of Biomedical Sciences, Houston, Texas, United States of America.