[1] Inst Univ Med Sociale & Prevent, Unite Epidemiol Canc, CH-1005 Lausanne, Switzerland
[2] Inst Univ Med Sociale & Prevent, Registre Vaudois Tumeurs, CH-1005 Lausanne, Switzerland
[3] Inst Univ Med Sociale & Prevent, Registre Neuchatelois Tumeurs, CH-1005 Lausanne, Switzerland
[4] Ist Ric Farmacol Mario Negri, Milan, Italy
[5] European Inst Oncol, Div Epidemiol & Biostat, Milan, Italy
[6] Univ Milan, Ist Stat Med & Biometria, I-20122 Milan, Italy