Stage Information
TNM Definitions
AJCC Stage Groupings
The staging system is clinical and based on the best possible estimate of the
extent of disease before treatment. The assessment of the primary tumor is
based on inspection and palpation when possible and by both indirect mirror
examination and direct endoscopy when necessary. The tumor must be confirmed
histologically, and any other pathological data obtained on biopsy may be
included. Head and neck magnetic resonance imaging or computed tomography
should be done prior to therapy to supplement inspection and palpation.[1]
Additional radiographic studies may be included. The appropriate nodal
drainage areas in the neck are examined by careful palpation.
The American Joint Committee on Cancer (AJCC) has designated staging by TNM
classification.[2]
TNM Definitions
Primary tumor (T)
- TX: Primary tumor cannot be assessed
- T0: No evidence of primary tumor
- Tis: Carcinoma in situ
Supraglottis
[Note: Supraglottis involves many individual subsites. Relapse-free survival may
differ by subsite and by T and N groupings within stage.]
Glottis
- T1: Tumor limited to the vocal cord(s), which may involve anterior or posterior
commissure, with normal mobility
- T1a: Tumor limited to one vocal cord
- T1b: Tumor involves both vocal cords
- T2: Tumor extends to supraglottis and/or subglottis and/or with impaired
vocal cord mobility
- T3: Tumor limited to the larynx with vocal cord fixation and/or invades paraglottic space, and/or minor thyroid cartilage erosion (e.g., inner cortex)
- T4a: Tumor invades through the thyroid cartilage and/or invades tissues
beyond the larynx (e.g., trachea, soft tissues of neck, including
deep extrinsic muscle of the tongue, strap muscles, thyroid, or esophagus)
- T4b: Tumor invades prevertebral space, encases carotid artery, or invades mediastinal structures
[Note: Glottic presentation may vary by volume of tumor, anatomic region involved, and
the presence or absence of normal cord mobility. Relapse-free survival may
differ by these and other factors in addition to T and N subgroupings within
the stage.]
Subglottis
- T1: Tumor limited to the subglottis
- T2: Tumor extends to vocal cord(s) with normal or impaired mobility
- T3: Tumor limited to larynx with vocal cord fixation
- T4a: Tumor invades cricoid or thyroid cartilage and/or invades tissues beyond the larynx (e.g., trachea, soft tissues of neck,
including deep extrinsic muscles of the tongue, strap muscles, thyroid, or esophagus)
- T4b: Tumor invades prevertebral space, encases carotid artery, or invades mediastinal structures
Regional lymph nodes (N)
- NX: Regional lymph nodes cannot be assessed
- N0: No regional lymph node metastasis
- N1: Metastasis in a single ipsilateral lymph node 3 cm or smaller in greatest
dimension
- N2: Metastasis in a single ipsilateral lymph node larger than 3 cm but 6 cm or smaller in greatest dimension, or in multiple ipsilateral lymph
nodes 6 cm or smaller in greatest dimension, or in bilateral or
contralateral lymph nodes 6 cm or smaller in greatest dimension
- N2a: Metastasis in a single ipsilateral lymph node larger than 3 cm
but 6 cm or smaller in greatest dimension
- N2b: Metastasis in multiple ipsilateral lymph nodes 6 cm or smaller in greatest dimension
- N2c: Metastasis in bilateral or contralateral lymph nodes 6 cm or smaller in greatest dimension
- N3: Metastasis in a lymph node larger than 6 cm in greatest dimension
In clinical evaluation, the actual size of the nodal mass should be measured,
and allowance should be made for intervening soft tissues. Most masses larger than 3 cm in diameter are not single nodes but confluent nodes or
tumors in soft tissues of the neck. There are three stages of clinically positive
nodes: N1, N2, and N3. The use of subgroups a, b, and c is not required but
recommended. Midline nodes are considered homolateral nodes.
Distant metastasis (M)
- MX: Distant metastasis cannot be assessed
- M0: No distant metastasis
- M1: Distant metastasis
AJCC Stage Groupings
Stage 0
Stage I
Stage II
Stage III
- T3, N0, M0
- T1, N1, M0
- T2, N1, M0
- T3, N1, M0
Stage IVA
- T4a, N0, M0
- T4a, N1, M0
- T1, N2, M0
- T2, N2, M0
- T3, N2, M0
- T4a, N2, M0
Stage IVB
- T4b, any N, M0
- Any T, N3, M0
Stage IVC
Evaluation of treatment outcome can be reported in various ways: locoregional
control, disease-free survival, determinate survival, and overall survival at 2
to 5 years. Preservation of voice is an important parameter to evaluate.
Outcome should be reported after initial surgery, initial radiation, planned
combined treatment, or surgical salvage of radiation failures. Primary source
material should be consulted to review these differences.
Because of clinical problems related to smoking and alcohol use in this
population, many patients succumb to intercurrent illness rather than to the
primary cancer.
Direct comparison of results of radiation versus surgery is complicated.
Surgical studies can report outcome based on pathologic staging, whereas
radiation studies must report on clinical staging, with the obvious problem of
understaging in patients treated with radiation, particularly in the neck. In
addition, radiation alone is often recommended for patients with poor
performance status, which leads to less favorable results.
References
-
Thabet HM, Sessions DG, Gado MH, et al.: Comparison of clinical evaluation and computed tomographic diagnostic accuracy for tumors of the larynx and hypopharynx. Laryngoscope 106 (5 Pt 1): 589-94, 1996.
[PUBMED Abstract]
-
Larynx. In: American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002, pp 47-57.
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