ABSTRACT
Head and neck cancer (HNC) rank fi fth in the list of the most common malignancies, with an estimated global incidence of 780,000 new cases per year and 350,000 cancer deaths worldwide every year (Argiris and Eng 2004, Argiris et al. 2008). A unifying feature, besides their location, is that approximately 95 percent of head and neck tumors are squamous cell carcinomas (HNSCC), which invariably appear from the upper aero digestive epithelium and are strongly associated with tobacco and/or
1State University of Londrina-Department of Clinical Surgery, Av. Robert Koch, 60 Vila Operária Zipe Code: 86038-440 Londrina-PR. Email: andrearmani@yahoo.com 2State University of Londrina-Department of General Pathology, Rodovia Celso Garcia Cid Pr 445 Km 380 Cx. Postal 6001, Zipe code: 86051-990 Londrina-PR. aEmail: alcecchini@uel.br bEmail: sara.sbernardes@gmail.com 3Laboratory of Pathophysiology and Free Radicals, Department of General Pathology-State University of Londrina, Rodovia Celso Garcia Cid km 445, Zipe code: 86051-990 Londrina, Paraná, Brazil. Email: cecchini@uel.br *Corresponding author
alcohol use. Approximately 570,000 new cases of HNSCC are diagnosed annually worldwide, representing fi ve percent of all tumors (Masters and Brockstein 2004, Ribeiro et al. 2001). About two-thirds of patients with HNSCC during an advanced stage disease, commonly involves regional lymph nodes. Distant metastasis at initial presentation is infrequent, in about 10 percent of patients (Argiris et al. 2008).
