Affiliation: | 1. Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, , Seattle, Washington;2. Division of Gastroenterology, Massachusetts General Hospital, , Boston, Massachusetts;3. Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, , Boston, Massachusetts;4. Department of Medical Oncology, Dana‐Farber Cancer Institute, , Boston, Massachusetts;5. Department of Epidemiology, Harvard School of Public Health, , Boston, Massachusetts |