1. From the Cross Cancer Institute; Division of Epidemiology, Prevention and Screening, Alberta Cancer Board; Departments of Oncology, Laboratory Medicine and Pathology, and Surgery, University of Alberta, Edmonton; Departments of Oncology and Clinical Neurosciences, University of Calgary and Tom Baker Cancer Center, Calgary, Alberta; London Regional Cancer Center, London; Northwestern Regional Cancer Center, Thunder Bay, Ontario, Canada; and M.D. Anderson Cancer Center, Houston, TX