1. Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
2. Department of Epidemiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
3. Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA
4. Center for Global Health, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA
5. Tanta Cancer Center, Tanta, Gharbiah 31111, Egypt
6. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA