Abstract
Worldwide, more than 550,000 new cases of head and neck cancer (HNC) occur each year, resulting inapproximately 300,000 deaths annually. It is the 6th most common cancer in both Europe and South America. Amajor reason for the high mortality rate for this cancer is the late stage of diagnosis for many patients. Accurateassessment of the prognosis of HNC cases also allows for appropriate tr…