T‐status

Characteristics 

TX

Primary tumour cannot be assessed

T0

No evidence of primary tumour 

Tis

Carcinoma in situ 

T1

Tumour 2 cm or less in greatest dimension 

T2

Tumour more than 2 cm but not more than 4 cm in greatest dimension 

T3 (oral cavity)

T3 (oropharynx)

Tumour more than 4 cm in greatest dimension

Tumour more than 4 cm in greatest dimension or involving lingual surface of epiglottis 

T4a 

Oral cavity

Oropharynx

Moderately advanced local disease

Tumour invades through cortical bone, into deep/extrinsic muscle of tongue (genioglossus, hyoglossus, palatoglossus and styloglossus), maxillary sinus or skin of face

Tumour invades any of the following: larynx deep/extrinsic muscle of tongue (genioglossus, hyoglossus, palatoglossus and styloglossus), medial pterygoid, hard palate and mandible 

T4b 

Oral cavity

Oropharynx

Very advanced local disease

Tumour invades masticator space, pterygoid plates or skull base, or encases internal carotid artery

Tumour invades any of the following: lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, skull base, or encases the carotid artery 

Note: superficial erosion alone of bone/tooth socket by gingival primary is not sufficient to classify a tumour as T4

N‐status

Characteristics

NX

Regional lymph nodes cannot be assessed

N0

No regional lymph node metastasis

N1

Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension

N2

Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension; or in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension

N2a. Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension

N2b. Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension

N2c

Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension

N3

Metastasis in a lymph node more than 6 cm in greatest dimension

Note: midline nodes are considered ipsilateral nodes

M‐Status

M0

No distant metastasis

M1

Distant metastasis

Stage 0

Tis

N0

M0

Stage I

T1

N0

M0

Stage II

T2

N0

M0

Stage III

T1, T2

N1

M0

T3

N0, N1

M0

Stage IVA

T1, T2, T3

N2

M0

T4a

N0, N1, N2

M0

Stage IVB

T4b

Any N

M0

Any T

N3

M0

Stage IVC

Any T

Any N

M1