aIstituto di Ricerche Farmacologiche “Mario Negri”, 20157 Milan, Italy
bServizio di Epidemiologia e Biostatistica, Centro di Riferimento Oncologico, 33081 Aviano (PN), Italy
cIstituto Tumori “Fondazione Pascale,” Cappella dei Cangiani, 80100 Naples, Italy
dInfection and Cancer Epidemiology Group, International Agency for Research on Cancer, F-69372 Lyon, cédex 08, France
eGastroenterology and Nutrient Unit, National Institute for Cancer Research, 16100 Genoa, Italy
fIstituto di Statistica Medica e Biometria, Università degli Studi di Milano, 20133 Milan, Italy
Correspondence to: Silvano Gallus, Istituto di Ricerche Farmacologiche “Mario Negri”, Via Eritrea 62, 20157 Milan, Italy
Tel: +39 02 39014 526; fax: +39 02 33200231;
e-mail: [email protected]
Received 10 December 2004 Accepted 9 January 2005