[1] Univ Milano Bicocca, Dept Clin Med & Prevent, Ctr Biostat Clin Epidemiol, Milan, Italy
[2] Univ Milano Bicocca, Dept Stat, Milan, Italy
[3] Mario Negri Inst Pharmacol Res, Dept Epidemiol, Milan, Italy
[4] Univ Milan, Dept Occupat Hlth, Milan, Italy
[5] European Inst Oncol, Div Epidemiol & Biostat, Milan, Italy
[6] Int Agcy Res Canc, F-69372 Lyon, France
[7] Int Prevent Res Inst, Lyon, France
[8] Univ Tehran Med Sci, Shariati Hosp, Digest Dis Res Ctr, Tehran, Iran
[9] Mt Sinai Sch Med, Tisch Canc Inst, New York, NY USA
[10] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden