Answer:
The TNM system is based on the clinical evaluation of the patient. Staging is used to compare the results of different treatments and between institutions, to estimate prognosis in terms of tumor control and patient survival, to plan treatment and to influence the choice of therapy. For tumors of the head and neck:
Tis Carcinoma in situ
T0 No evidence of primary tumor
T1 Less than 2cm
T2 More than 2cm but not greater than 4cm
T3 More than 4cm
T4 Invading adjacent structures
N0 No regional node involvement
N1 Ipsilateral regional nodes less than 3cm
N2 Single ipsilateral node 3 to 6cm or multiple ipsilateral nodes less than 6cm; or bilateral or contralateral nodes, not greater than 6cm
N3 Massive ipsilateral nodes or contralateral nodes (greater than 6cm)
M0 No evidence of distant metastases
M1 Metastases beyond the cervical lymph nodes
Stage 0 Tis N0 M0
Stage I T1 N0 M0
Stage II T2 N0 M0
Stage III T3 N0 M0
T1 N1 M0
T2 N1 M0
T3 N1 M0
Stage IV T4 N0/N1 M0
Any T, N2/N3 M0
Any T, Any N, M1
Classification for primary tumor of the larynx:
Tx Primary cannot be assessed.
T0 No evidence of primary.
Tis Carcinoma in situ.
Supraglottis:
T1 Tumor limited to one subsite of supraglottis or glottis with normal vocal cord mobility.
T2 Tumor invades more than one subsite of supraglottis with normal vocal cord mobility.
T3 Tumor limited to larynx with vocal cord fixation or invades postcricoid area, medial wall of pyriform sinus, or preepiglottic tissues.
T4 Tumor invades through thyroid cartilage or extends to other tissues beyond the larynx, e.g., to oropharynx, soft tissues of neck.
Glottis:
T1 Tumor limited to vocal cord(s) (may involve anterior or posterior commissures) with normal mobility.
T2 Tumor extends to supraglottis or subglottis, or with impaired vocal cord mobility.
T3 Tumor limited to the larynx with vocal cord fixation.
T4 Tumor invades through thyroid cartilage or extends to other tissues beyond the larynx, e.g. to oropharynx or soft tissues of the neck.
Subglottis:
T1 Tumor limited to the subglottis.
T2 Tumor extends to vocal cord(s) with normal or impaired mobility.
T3 Tumor limited to the larynx with vocal cord fixation.
T4 Tumor invades through cricoid or thyroid cartilage or extends to other tissue beyond the larynx, e.g. to oropharynx or soft tissues of neck.