1. Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland
2. Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
3. North Dakota Statewide Cancer Registry, Grand Forks
4. Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
5. Iowa Cancer Registry, Department of Epidemiology, The University of Iowa, Iowa City