TNM Staging Guide 5th Edition eBook

II. American Joint Committee on Cancer (AJCC) Tumor Staging by Site

A. Oral Cavity The anterior border is the junction of the skin and vermilion border of the lip. The posterior border is formed by the junction of the hard and soft palates superiorly, the circumvallate papillae inferiorly, and the anterior tonsillar pillars laterally. The various sites within the oral cavity include the lip, gingival, hard palate, buccal mucosa, floor of mouth, anterior two-thirds of tongue, and retromolar trigone. Recent data has shown that primary tumor depth of invasion (DOI) has a significant impact on disease outcomes and compliments the previous criteria used for T-stage classification. As a result, the new staging system incorporated DOI to reflect this influence on prognosis.

PRIMARY TUMOR (T) TX Primary tumor cannot be assessed T0 No evidence of primary tumor Tis Carcinoma in situ T1

Tumor 2 cm or less in greatest dimension and is less than or equal to 5mm Depth of Invasion (DOI) Tumor more than 2 cm but not greater than 4 cm in greatest dimen- sion or is greater than 5 mm DOI but not more than 10mm DOI Tumor more than 4 cm in greatest dimension or is greater than 10mmDOI Moderately advanced local disease* (Lip) Tumor invades through cortical bone or involves the inferior alveolar nerve, floor of mouth, or skin of face (i.e., chin or nose) (Oral cavity) Tumor invades adjacent structures only (e.g., through cortical bone of the mandible or maxilla, or involves the maxillary sinus or skin of the face)

T2

T3

T4a

T4b Very advanced local disease

Tumor invades masticator space, pterygoid plates, or skull base and/ or encases internal carotid artery

*Note: Superficial erosion alone of bone/tooth socket by gingival primary is not sufficient to classify as T4.

14 TNM Staging of Head and Neck Cancer and Neck Dissection Classification