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The oral cavity is the most common site for squamous cell carcinoma (SCC) of the head and neck, a disease that inflicts substantial morbidity and mortality worldwide.1,2 The primary modality of treatment for both index and recurrent cases is surgical resection, though many patients present with advanced stage disease and require a multidisciplinary approach. A number of issues that impact surgical treatment must be considered, including operative access, need for mandibulectomy, need for neck dissection, and the type of reconstruction. Recovery and rehabilitation often require ancillary services that include dental, prosthodontics, physical therapy, as well as speech and swallow therapy. Patients with adverse pathologic features benefit from postoperative radiation; lymph node extracapsular spread or positive surgical margins in particular suggest need for chemoradiation.3 The current diagnosis and management of oral cavity malignancies are reviewed.
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ETIOLOGY AND INCIDENCE
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Oral cavity malignancies comprise 30% of all head and neck cancers, with approximately 22,000 cases per year worldwide (excluding lip cancers). Over 95% of oral cavity cancers are SCCs that arise from carcinogen exposure. In the United States the most common subsite is the oral tongue due to smoking. However, in areas such as India, the most common subsite is the buccal mucosa due to the high prevalence of betel nut and other smokeless tobacco consumption.
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Tobacco and alcohol are the two most important risk factors associated with the development of oral cavity SCC. For both products, the risk is both dose-dependent and synergistic, with tobacco serving a primary role and alcohol enhancing or promoting its carcinogenic effects. The irritant effects of alcohol induce a chemical burn that increases cell membrane permeability and facilitates introduction of toxic agents. Notably, 75% of oral cavity cancers are found within a zone that encompasses only 10% of the surrounding mucosal surface area.4 This region extends from the anterior floor of mouth, around the lateral tongue, and up to the retromolar trigone and anterior tonsillar fossa. This is most likely due to the natural flow and pooling of contaminated saliva.
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Compared to nonsmokers, smoking confers a 1.9-fold risk for males and threefold risk for females, with proportionally escalating risk for increased number of years smoking and number of cigarettes smoked per day.5 Similarly, alcohol alone confers a 1.7-fold risk to males drinking one to two glasses per day compared with nondrinkers, rising to threefold for heavier consumption. Smokers who at least drink two packs per day and those who concurrently drink at least four glasses per day have been found to combinedly harbor a 35-fold increased risk for developing oral cavity SCC compared to normal controls. Separately, individuals who chew smokeless tobacco have a fourfold higher risk of developing an oral cavity malignancy compared with nonusers. Women in India who practice reverse smoking (puffing cigars with the burning end in the mouth) have a 47-fold higher risk of ...