[1] Mario Negri Inst Pharmacol Res, I-20157 Milan, Italy
[2] Ctr Riferimento Oncol, Serv Epidemiol & Biostat, I-33081 Aviano, Pordenone, Italy
[3] Inst Univ Med Sociale & Prevent, Unite Epidemiol Canc, CH-1005 Lausanne, Switzerland
[4] Policlin Monza, Milan, Italy
[5] Ist Tumori Fdn Pascale, Serv Epidemiol, Naples, Italy
[6] Int Agcy Res Canc, F-69372 Lyon, France
[7] Univ Milan, Ist Stat Med & Biometria, I-20122 Milan, Italy