1. Head and Neck Division, European Institute of Oncology, Milan, Italy
2. Division of Head and Neck Surgical Oncology, Istituto Nazionale dei Tumori, Milan, Italy
3. Institute of Medical Statistics and Biometry, Università degli Studi di Milano, Milan, Italy
4. Unit of Medical Statistics and Biometry, Istituto Nazionale dei Tumori, Milan, Italy
5. Division of Experimental Oncology, Istituto Nazionale dei Tumori, Milan, Italy
6. Pathology Division, Ospedale di Sondrio, Sondrio, Italy
7. Scientific Director's Office, European Institute of Oncology, Milan, Italy
8. Senology Division, Fondazione Maugeri, Pavia, Italy
9. Division of Diagnostic Oncology and Out‐Patient Clinic, Istituto Nazionale dei Tumori, Milan, Italy