1 Department of Dermatology and Allergology, Ludwig-Maximilian University Munich, Munich, Germany.
2 Oncologic Surgery, A. Businco Oncologic Hospital, Cagliari, Italy.
3 Department of Otolaryngology-Head Neck Surgery, University of Pavia, IRCCS Policlinico San Matteo Foundation, Pavia, Italy.
4 Department of Oncology, Copenhagen University Hospital Herlev and Gentofte, Herlev, Denmark.
5 Department of Surgical Oncological and Gastroenterological Sciences (DISCOG), University of Padua, Padua, Italy. Electronic address: [email protected].