1 Department of Epidemiology, Istituto di Ricerche Farmacologiche 'Mario Negri', Milan.
2 Department of Epidemiology, Istituto di Ricerche Farmacologiche 'Mario Negri', Milan; Department of Occupational Health, Section of Medical Statistics, University of Milan, Milan, Italy.
3 National Cancer Institute, Bethesda.
4 Mayo Clinic, Rochester.
5 University of California-San Francisco, San Francisco.
6 The University of Texas M.D Anderson Cancer Center, Houston.
7 Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven.
8 Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, USA.
9 Toronto General Hospital, Toronto.
10 Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
11 National Institute for Public Health and the Environment (RIVM), Bilthoven; Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
12 Unit of Epidemiology and Biostatistics, Centro di Riferimento Oncologico, Aviano (PN), Italy.
13 Epidemiology Research Unit, Research Centre (CRCHUM), Montréal, Canada.
14 Public Health, Women's and Children's Hospital, Adelaide SA, Australia.
15 Cancer Center and Institute of Oncology, Warsaw, Poland.
16 Louisiana State University, New Orleans.
17 Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, USA.
18 Dalla Lana School of Public Health, University of Toronto, Toronto, Canada; Cancer Care Ontario, Toronto, Canada.
19 European Institute of Oncology, Milano, Italy.
20 Catalan Institute of Oncology, Barcelona, Spain.
21 International Prevention Research Institute, Lyon, France; The Tisch Cancer Institute, Mount Sinai School of Medicine, New York, USA. Electronic address: paolo.boffetta@mssm.edu.