Gingival cancers occur most commonly (80%) in the lower gingiva posterior to the bicuspids. For both sites, trismus is an ominous sign indicating extension to masseter or pterygoid muscles. Clinical staging criteria are similar to those for other oral sites. Overall, regional metastases occur in approximately 15% of gingival cancers. Recently, occult nodal metastases have been documented in as high as 30% of buccal cancers and elective neck dissection recommended in all but the earliest of cancers. Exophytic tumors tend to be papillary or verrucous in appearance and can be confused with benign hyperkeratosis.
Small, superficial gingival cancers can be effectively treated with surgical resection with excellent preservation of function. Generally, the amount of bone resected for small lesions is minimal and resection can be accomplished transorally. Even larger lesions requiring partial maxillectomy or alveolectomy can be resected without external incision. External beam irradiation is not as effective in local tumor control once gross bone involvement has occurred. The intermediate (T2 or larger) lesions are best handled surgically; the risk of osteoradionecrosis is thereby avoided. For large lesions (T3 and T4), segmental mandibulectomy or maxillectomy is required and adjuvant radiation is frequently recommended. Elective neck dissection is not mandated unless the en bloc resection of a large primary tumor requires neck exposure. However, for patients in whom no neck dissection is performed, elective neck irradiation should be considered. Clinically positive neck nodes warrant neck dissection combined with resection of the primary tumor.
Buccal carcinomas of early stage (I or II) can be treated equally well with surgery or radiation. Radiation therapy offers the advantage of including the draining lymphatics in the treatment fields, but also risks posttreatment fibrosis and trismus. Large primary tumors or tumors with regional metastases are managed surgically, with the need for adjuvant radiation determined by the adequacy of resection and risk of suspected residual disease.
Overall survival rates for gingival and buccal cancers depend on tumor size, bone involvement, and node metastases. The 5-year survival rates for lower gingival lesions do not differ from those for the upper gingiva and range from 78% for stage I to 15% for stage IV disease. Surgical results are clearly superior to those of radiation when bone involvement is present. Survival rates (5-year) for stages I and II buccal carcinomas range from 65% to 75%. Determinant survival for stages III and IV disease varies from 20% to 30%. For both gingival and buccal mucosal cancers, overall survival rates have improved over recent years as surgical management has replaced radiation therapy as the primary treatment.
Revision date: July 7, 2011
Last revised: by Janet A. Staessen, MD, PhD