1. Departments of Diagnostic, Clinical and Public Health Medicine, Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), University of Modena and Reggio Emilia, Padiglione De Sanctis, Via Amendola 2, 42122 Reggio Emilia, Italy
2. Department of Biostatistics, University of California Los Angeles Fielding School of Public Health, Los Angeles, CA 90095-1772, USA
3. Epidemiology and Prevention Unit, National Cancer Institute, Via Venezian 1, 20133 Milan, Italy
4. Department of Surgery, Medicine, Odontoiatrics and Morphological Sciences, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy