1. Department of Internal Medicine; Division of Hematology-Oncology, University of Nebraska Medical Center; Omaha Nebraska
2. Department of Biostatistics; University of Nebraska Medical Center, College of Public Health; Omaha Nebraska
3. Department of Internal Medicine; Division of Hematology-Oncology, Yale University; New Haven Connecticut
4. Department of Epidemiology; University of Nebraska Medical Center, College of Public Health; Omaha Nebraska
5. Clinical Research Division; Fred Hutchinson Cancer Research Center, Division of Medical Oncology, University of Washington School of Medicine; Seattle Washington