1. Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan, Italy
2. Oncology and Hemato-oncology Department, University of Milan, Milan, Italy
3. Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
4. Unit of Medical Oncology 2, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
5. Klinik fur Innere Med IV, University Clinic Halle, Halle, Germany
6. GI Oncology, Sarah Cannon Research Institute, Nashville, Tennessee, USA
7. Unit of Medical Oncology 1, Department of Clinical and Experimental Oncology, Istituto Oncologico Veneto, IRCCS, Padua, Italy
8. Clinical Epidemiology Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy