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Clinical Findings

Patients with cancer of the oral cavity usually present with ulcerated cancers that have been present for weeks or months. They are typically men aged 50-70 years with a history of heavy tobacco and alcohol use. Dental hygiene is frequently poor, and areas of leukoplakia and erythroplakia can be seen adjacent to the cancer. Submandibular or jugular chain lymph nodes are palpable in 25-35% of patients. Pain is usually not a prominent feature but may become severe with deep infiltration.

T STAGE: ORAL CANCER

T1 Tumor 2 cm or less in greatest dimension T2 Tumor more than 2 cm but not more than 4 cm in greatest dimension T3 Tumor more than 4 cm in greatest dimension T4 Lip: Tumor invades adjacent structures (eg, through cortical bone, tongue, skin) T4 Oral cavity: Tumor invades adjacent structures (eg, through cortical bone, into deep [extrinsic] muscle of tongue, maxillary sinus, skin)

Treatment

A. Primary Cancer

Surgical excision is the treatment of choice for most oral cancers. Cancers of the vermilion surface of the lip are best treated with full-thickness excision of the lip. Lateral margins of 5 mm of uninvolved lip are taken with the cancer. The defect is closed primarily when one-third or less of the lip is excised. When excision of more than one-third of the lip is required, closure is achieved by transposition of a segment of the opposite lip on a vascular pedicle (Abbe flap). When the entire vermilion of the lip has been damaged, vermilionectomy (lip shave) can be performed along with excision of the cancer and a new vermilion surface created by advancing the labial mucosa.

Within the oral cavity, small cancers can usually be excised through the open mouth taking a margin of 1 cm of normal-appearing tissue. Small defects are closed by direct suture or split-thickness skin grafts. Larger cancers (> 2 cm) require more extensive exposure (ie, cheek flap), resection, and subsequent reconstruction. For cancers involving bone, marginal or segmental resection of the mandible is performed. A composite resection involves resection of an oral cancer, resection of a portion of the mandible, and a neck dissection.

Radiation therapy is an alternative to surgery for oral cancers smaller than 4 cm in diameter (T1 and T2 cancers). The side effects of mucositis, xerostomia, and osteoradionecrosis of the mandible must be balanced against potential advantages. T3 and T4 cancers are usually treated with combined surgery and radiation therapy to improve the rate of local control.

B. Management of Neck Metastases

Clinically apparent cervical lymph node metastases can be treated by radical neck dissection, which involves removal of all the lymphatic tissue of the neck along with the sternocleidomastoid muscle, internal jugular vein, and spinal accessory nerve. To save structures not directly involved by cancer, modified neck dissection is performed. A modified radical neck dissection always preserves the spinal accessory nerve, while a functional neck dissection always preserves the sternocleidomastoid muscle, the internal jugular vein, and the spinal accessory nerve. Selective neck dissections involve only certain cervical lymph node levels. For example, levels I, II, and III cervical lymph nodes and cervical lymph nodes in the upper portion of level V are removed with a supraomohyoid neck dissection while preserving the sternocleidomastoid muscle, the internal jugular vein, and the spinal accessory nerve.

When modified neck dissections are performed, adjuvant radiation therapy to the neck is frequently required. It is recommended for use when more than two cervical lymph nodes contain metastases, when more than one level of cervical lymph nodes are involved, or when there is extension of metastases through the capsule of a cervical lymph node. Occult cervical lymph node metastases are present in 20-30% of patients with oral cancers (other than lip, buccal mucosa, or hard palate cancers) who present with a clinically negative neck. Elective neck dissections have been advocated for these patients to more accurately stage the cancer and to prevent the need for a later and probably more radical neck dissection when the cervical lymph node metastases becomes clinically apparent. A supraomohyoid neck dissection is the dissection of choice in the elective situation.

Prognosis

The five-year survival rates for cancer of the oral cavity with appropriate treatment are as follows: stage I, 72-88%; stage II, 46-80%; stage III, 36-66%; and stage IV, 11-32%. Buccal mucosa cancers have a better prognosis than tongue or hard palate cancers.

References