Primary tumor (T) |
T category | T criteria |
TX | Primary tumor cannot be assessed |
T0 | No tumor identified, but EBV-positive cervical node(s) involvement |
Tis | Tumor in situ |
T1 | Tumor confined to nasopharynx, or extension to oropharynx and/or nasal cavity without parapharyngeal involvement |
T2 | Tumor with extension to parapharyngeal space, and/or adjacent soft tissue involvement (medial pterygoid, lateral pterygoid, prevertebreal muscles) |
T3 | Tumor with infiltration of bony structures at skull base, cervical vertebra, pterygoid structures, and/or paranasal sinuses |
T4 | Tumor with intracranial extension, involvement of cranial nerves, hypopharynx, orbit, parotid gland, and/or extensive soft tissue infiltration beyond the lateral surface of the lateral pterygoid muscle |
Regional lymph nodes (N) |
N category | N criteria |
NX | Regional lymph nodes cannot be assessed |
N0 | No regional lymph node metastasis |
N1 | Unilateral metastasis in cervical lymph node(s) and/or unilateral or bilateral metastasis in retropharyngeal lymph node(s), 6 cm or smaller in greatest dimension, above the caudal border of cricoid cartilage |
N2 | Bilateral metastasis in cervical lymph node(s), 6 cm or smaller in greatest dimension, above the caudal border of cricoid cartilage |
N3 | Unilateral or bilateral metastasis in cervical lymph node(s), larger than 6 cm in greatest dimension, and/or extension below the caudal border of cricoid cartilage |
Distant metastasis (M) |
M category | M criteria |
M0 | No distant metastasis |
M1 | Distant metastasis |
Prognostic stage groups |
When T is... | And N is... | And M is... | Then the stage group is... |
Tis | N0 | M0 | 0 |
T1 | N0 | M0 | I |
T1, T0 | N1 | M0 | II |
T2 | N0 | M0 | II |
T2 | N1 | M0 | II |
T1, T0 | N2 | M0 | III |
T2 | N2 | M0 | III |
T3 | N0 | M0 | III |
T3 | N1 | M0 | III |
T3 | N2 | M0 | III |
T4 | N0 | M0 | IVA |
T4 | N1 | M0 | IVA |
T4 | N2 | M0 | IVA |
Any T | N3 | M0 | IVA |
Any T | Any N | M1 | IVB |