1. a Division of Medical Oncology A, National Cancer Institute, Aviano, Italy;
2. c Oncology and Hematology Department, Istituto Clinico Humanitas, Rozzano (MI), Italy;
3. d Oncology Unit, San Paolo's Hospital, University of Milan, Milan, Italy;
4. e Unit of Lymphoid Malignancies, Department of Onco-Hematology, San Raffaele Scientific Institute, Milan, Italy
5. b Epidemiology Unit, National Cancer Institute, Aviano, Italy;