Malignant tumors of the oral cavity and oropharynx are predominantly (greater than 90–95%) squamous cell carcinomas. Less common tumors include minor salivary gland tumors (especially on the hard palate), verrucous carcinomas, lymphomas, melanomas, and sarcomas. The most common risk factors are tobacco, smoked and smokeless, and alcohol abuse. Less common factors include poorly fi tting dentures, poor dentition with irregular surfaces, and poor oral hygiene. Nonsmokers can also be diagnosed with oral cavity and oropharynx cancer. Among nonsmokers, human papillomavirus (HPV) has recently been associated with malignancies of the oropharynx, and may portend better outcomes when compared to those without HPV infection. Malignancies of the oral cavity and oropharynx account for approximately 4% of all newly diagnosed nonskin malignancies, with a 2:1 male predominance.
Approximately 34,000 new cases are diagnosed each year. Two-thirds of these are in the oral cavity and one-third in the oropharynx. Oral cancer accounts for an estimated 7,550 deaths yearly (Cancer Facts and Figures, 2007). While oral cavity and oropharynx cancer accounts for only a small number of all new cancers, the functional problems created by these tumors and their treatment are signifi cant. Oral cavity and pharyngeal dysfunction affects speech, oral competence, the fi rst and second (oral and pharyngeal) phases of swallowing, and in some instances, the ability to adequately protect the airway. Even small tumors may result in signifi cant weight loss due to pain, dysphagia, and odynophagia, resulting in malnutrition. Dysarthria affects interpersonal communication and frequently results in withdrawal from public situations.
An important consideration in the treatment of oral cavity and oropharyngeal malignancies is the high incidence of second primary tumors. These tumors may be synchronous or metachronous, and occur in approximately 20% of patients. More than half of these second primary tumors are found in the upper airway and digestive tract, most commonly in the esophagus, larynx, oral cavity, and pharynx, as a result of the widespread carcinogenic effects of tobacco and alcohol. Second primary cancers of the lung are also common and for the same reasons. Pretreatment evaluation with chest radiography or computed tomography (CT), positron emission testing (PET), and rigid laryngoscopy and esophagoscopy, is advised to fully stage these tumors.