| Primary tumor (T) | |||
| T category | T criteria | ||
| T0 | No primary identified | ||
| T1 | Tumor 2 cm or smaller in greatest dimension | ||
| T2 | Tumor larger than 2 cm but not larger than 4 cm in greatest dimension | ||
| T3 | Tumor larger than 4 cm in greatest dimension or extension to lingual surface of epiglottis | ||
| T4 | Moderately advanced local disease. Tumor invades the larynx, extrinsic muscle of tongue, medial pterygoid, hard palate, or mandible or beyond.* | ||
| * Mucosal extension to lingual surface of epiglottis from primary tumors of the base of the tongue and vallecula does not constitute invasion of the larynx. | |||
| Regional lymph nodes (N) - Clinical N (cN) | |||
| N category | N criteria | ||
| NX | Regional lymph nodes cannot be assessed | ||
| N0 | No regional lymph node metastasis | ||
| N1 | One or more ipsilateral lymph nodes, none larger than 6 cm | ||
| N2 | Contralateral or bilateral lymph nodes, none larger than 6 cm | ||
| N3 | Lymph node(s) larger than 6 cm | ||
| Distant metastasis (M) | |||
| M category | M criteria | ||
| M0 | No distant metastasis | ||
| M1 | Distant metastasis | ||
| Prognostic stage groups - Clinical | |||
| When T is... | And N is... | And M is... | Then the stage group is... |
| T0, T1, or T2 | N0 or N1 | M0 | I |
| T0, T1, or T2 | N2 | M0 | II |
| T3 | N0, N1, or N2 | M0 | II |
| T0, T1, T2, T3, or T4 | N3 | M0 | III |
| T4 | N0, N1, N2, or N3 | M0 | III |
| Any T | Any N | M1 | IV |
