1. From the Fred Hutchinson Cancer Research Center, Cancer Prevention Program, Seattle, WA (AB, MLN, BS, KLaC, AMcT, and CMU); the Departments of Epidemiology (AB, EAK, AMcT, and CMU), Laboratory Medicine (MHW, BW, and ZCL), and Pathobiology (EAK), University of Washington, Seattle, WA; and the Department of Public Health Sciences, University of Alberta, Edmonton, AB (YY)