1. Department of Surgery; Fondazione IRCCS Istituto Nazionale Tumori; Milan Italy
2. Department of Clinical Epidemiology and Trial Organisation; Fondazione IRCCS Istituto Nazionale Tumori; Milan Italy
3. Division of Surgical Oncology, Department of Surgery; Brigham and Women's Hospital; Boston Massachusetts
4. Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute; Harvard Medical School; Boston Massachusetts