1. Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA
2. Department of Community Health and Social Medicine, School of Medicine, City University of New York, New York, NY, USA
3. Gharbiah Cancer Society and Gharbiah Cancer Registry, Tanta 31512, Egypt
4. Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA
5. Department of Obstetrics and Gynecology, University of Nebraska Medical Center, Omaha, NE, USA
6. Department of Epidemiology, University of Texas, M.D. Anderson Cancer Center, Houston, TX, USA