1. Department of Medical and Surgical Sciences University of Bologna Bologna Italy
2. Department of Clinical Sciences and Community Health University of Milan Milan Italy
3. Department of Biomedical and Clinical Sciences L. Sacco University of Milan Milan Italy
4. Mexico National Institute of Public Health Morelos Mexico
5. Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center Tokyo Japan
6. Nikkei Disease Prevention Center São Paulo Brazil
7. Department of Biostatistics Yale School of Public Health, Yale School of Medicine New Haven Connecticut USA
8. Facultad de Medicina, UNAM Coyoacán Mexico
9. Digestive Oncology Research Center Digestive Disease Research Institute, Tehran University of Medical Sciences Tehran Iran
10. Digestive Disease Research Center Ardabil University of Medical Sciences Ardabil Iran
11. Department of Epidemiology and Environmental Health School of Public Health and Health Professions, University at Buffalo Buffalo New York USA
12. Department of Epidemiology UCLA Fielding School of Public Health and Jonsson Comprehensive Cancer Center Los Angeles California USA
13. Department of Epidemiology EPIUnit‐Instituto de Saúde Pública da Universidade do Porto Porto Portugal
14. Departamento de Ciências da Saúde Pública e Forenses e Educação Médica Faculdade de Medicina da Universidade do Porto Porto Portugal
15. Stony Brook Cancer Center Stony Brook University Stony Brook New York USA