Oral Cavity cancer
Both tumor and treatment significantly compromise speech and deglutition, particularly for those patients in whom cancer involves the tongue, the floor of the mouth, or the mandible. Furthermore, the diversity of potential sites of cancer development in the oral cavity and variations of lymphatic drainage and rates of node metastases lend added complexity to treatment planning. Despite the fact that this region is readily amenable to visual examination and bimanual palpation, more than 50% of patients are diagnosed in advanced stages. The current T-staging of oral cavity primaries is presented in

Table 90-4.

Lip cancer
SCCs of the lip are the most common oral cavity cancers. Over 90% occur on the lower lip, usually on the exposed vermilion border, midway between the midline and the oral commissure. Upper lip cancers most commonly are basal cell carcinomas. Well-differentiated and verrucous cancers rarely metastasize. Poorly differentiated and spindle cell varieties tend to grow aggressively and metastasize commonly. Perineural infiltration of large nerves is indicative of aggressive disease.

The treatment of lip cancers must consider adequate removal of the disease and yet provide the patient with a lip that functions in speech and chewing and that retains oral competence and adequate cosmesis. These goals are achieved equally well with either primary radiation or surgery when the tumors are less than 2 cm in size or are very superficial. Larger lesions, however, are best treated with surgical resection and reconstruction, which allows for greater accuracy in evaluating the extent of tumor and nerve or lymphatic involvement. Frequently, adjacent precancerous changes are present that can also be treated with surgery (lip shaving and advancement) to prevent recurrences or the development of second primary tumors. For larger lesions, primary reconstruction with local, regional, and sometimes free tissue flaps avoids defects that result from tissue loss with radiotherapy, provides for future reconstructive and treatment options, and eliminates the risk of osteoradionecrosis of the mandible. Lesions demonstrating extensive infiltration, bone involvement, or lymphatic metastases are increasingly managed with combined surgery and postoperative radiation.

Radiation therapy techniques for management of lip cancers include external irradiation, interstitial implants, and combinations of both. Local tumor control rates with irradiation exceed 80%, with determinant survival at 5 years (including surgical salvage) in excess of 95%. Similar tumor control and survival rates are reported with primary surgical excision. Regional metastasis decreases the survival rates to 36% to 55%. Five-year survival rates for patients with carcinomas of the upper lip are lower than for those with lower-lip lesions and range from 40% to 60%. Involvement of both lips and the lateral commissure is uncommon. The prognosis for commissure lesions is not as good as for cancers of other areas of the lip. Cross and colleagues report a 5-year survival rate of 34% for patients with oral commissure carcinoma (

Table 90-5).