AJCC 8th Edition Head & Neck Staging Guidelines

Larynx

Overview
  • Laryngeal cancers are staged differently depending on their site of origin (supraglottic, glottic, or subglottic).
  • Boundaries of the supraglottis, glottis, and subglottis:
    • The supraglottis and the glottis are divided by an imaginary line that travels through the midpoint of the laryngeal ventricle (most commonly accepted definition).
    • The glottis and subglottis are divided by an line that is 1 cm below the line described above
    • The inferior border of the cricoid forms the inferior limit of the subglottis.
Changes from the AJCC 7th Edition
  • Mostly unchanged from the 7th Edition.
  • T0 has been removed as a category
  • This staging system now uses the new shared nodal and group staging described previously.
T-Categorization

Supraglottic Carcinoma

T Category Criteria
TX

Primary tumour cannot be assessed
Tis

Carcinoma in situ.
T1

Tumour limited to 1 subsite of the supraglottis only and with normal vocal fold mobility.
T2
  • Tumour involves more than 1 subsite of the supraglottis OR has glottic extension OR has hypopharyngeal or oropharyngeal mucosal extension. (eg. mucosa of base of tongue, vallecula, medial wall of pyriform sinus).
  • AND without vocal fold fixation.
T3
  • Vocal fold fixation.
  • OR invades any of the following: postcricoid area, preepiglottic space, paraglottic space, and/or inner cortex of thyroid cartilage.
  • OR extension to the mucosa of the esophagus.
T4 Moderately advanced (T4a) or very advanced (T4b) disease
T4a
  • Moderately advanced local disease
  • Tumor invades through the outer cortex of the thyroid cartilage and/or invades tissues beyond the larynx (e.g., trachea, esophagus, soft tissues of neck, thyroid, extralaryngeal strap muscles.).
T4b
  • Very advanced local disease
  • Tumour invasion of the prevertebral fascia, carotid artery encasement, or involves mediastinal structures.

Glottic Carcinoma

T Category Criteria
TX

Primary tumour cannot be assessed
Tis

Carcinoma in situ.
T1 Tumour limited to the vocal folds only.
T1a

Tumour limited to one vocal fold only.
T1b

Tumour involves both vocal folds (eg. involving the anterior commissure).
 
T2
  • Tumour extends into the supraglottis or subglottis.
  • OR vocal fold paresis.
T3
  • Vocal fold fixation.
  • OR invasion of the paraglottic space, and/or inner cortex of thyroid cartilage.
T4 Moderately advanced (T4a) or very advanced (T4b) disease
T4a
  • Moderately advanced local disease
  • Tumor invades through the outer cortex of the thyroid cartilage and/or invades tissues beyond the larynx (e.g., trachea, esophagus, soft tissues of neck, thyroid, extralaryngeal strap muscles.).
T4b
  • Very advanced local disease
  • Tumour invasion of the prevertebral fascia, carotid artery encasement, or involves mediastinal structures.

Subglottic Carcinoma

T Category Criteria
TX

Primary tumour cannot be assessed
Tis

Carcinoma in situ.
T1

Tumour is limited to the subglottis.
T2
  • Tumour extends into the glottis.
  • OR vocal fold paresis.
T3
  • Vocal fold fixation.
  • OR invasion of the paraglottic space, and/or inner cortex of thyroid cartilage.
T4 Moderately advanced (T4a) or very advanced (T4b) disease
T4a
  • Moderately advanced local disease
  • Tumor invades through the thyroid or cricoid and/or invades tissues beyond the larynx (e.g., trachea, esophagus, soft tissues of neck, thyroid, extralaryngeal strap muscles.).
T4b
  • Very advanced local disease
  • Tumour invasion of the prevertebral fascia, carotid artery encasement, or involves mediastinal structures.

General Rules

  • Subsites of the supraglottis include:
    1. Suprahyoid epiglottis
    2. Infrahyoid epiglottis
    3. False vocal folds
    4. Arytenoids
    5. Aryepiglottic folds
  • Although the T-categorization for the supraglottis, glottis, and subglottis are different, there are a few common features that make this easier to remember:
    1. Vocal fold paresis makes you at least T2
    2. Vocal fold immobility makes you at least T3
    3. Invasion of the inner cortex of the thyroid cartilage makes you at least T3
    4. T4a is always defined by invasion into TESTES (mnemonic):
      • T → Thyroid
      • E → Esophagus
      • S → Soft tissues of neck (including tongue extrinsics)
      • T → Trachea
      • ES → Extralaryngeal straps
    5. T4a is also defined by invasion through the outer cortex of the thyroid cartilage (ie. through-and-through).
    6. T4b is always 'non-resectable disease' and this includes carotid artery encasement, invasion of mediastinal structures, or involvement of the prevertebral fascia.
  • T2 is also defined by mucosal involvement of adjacent sites. For instance, in the supraglottis this is either superior extension to the oropharynx/hypopharynx, or inferior extension to the glottis. In the glottis this is either superior extension to the supraglottis or inferior extension to the subglottis. In the subglottis this is superior extension to the glottis.
  • T3 is also defined by extension into adjacent spaces that increase propensity to spread (such as the paraglottic space in all 3 areas, and the pre-epiglottic space in the supraglottis).
N-Categorization

Clinical Nodal Categorization
(Shared Categorization System)

N Category Criteria
NX

Regional lymph nodes cannot be assessed.
N0

No regional lymph node metastasis.
N1
  • Single ipsilateral lymph node that is 3 cm or less in maximal dimension without extranodal extension
N2
N2a
  • Single ipsilateral lymph node that is > 3 cm but ≤ 6 cm in maximal dimension without extranodal extension
N2b
  • Mulple ipsilateral lymph nodes that are ≤ 6 cm in maximal dimension without extranodal extension
N2c
  • Bilateral or contralateral lymph nodes that are ≤ 6 cm in maximal dimension without extranodal extension
N3
N3a

Metastasis in any lymph node > 6 cm without extranodal extension
N3b

Metastasis in any lymph node with clinically overt extranodal extension.

Pathologic Nodal Categorization
(Shared Categorization System)

N Category Criteria
NX

Regional lymph nodes cannot be assessed.
N0

No regional lymph node metastasis.
N1
  • Single ipsilateral lymph node that is 3 cm or less in maximal dimension without extranodal extension
N2
N2a
  • Single ipsilateral lymph node that is > 3 cm but ≤ 6 cm in maximal dimension without extranodal extension
  • OR metastasis to a single ipsilateral lymph node that is 3 cm or less in maximal dimension WITH extranodal extension
N2b
  • Mulple ipsilateral lymph nodes that are ≤ 6 cm in maximal dimension without extranodal extension
N2c
  • Bilateral or contralateral lymph nodes that are ≤ 6 cm in maximal dimension without extranodal extension
N3
N3a

Metastasis in any lymph node > 6 cm without extranodal extension
N3b
  • Metastasis in any lymph node with clinically overt extranodal extension.
  • EXCEPT if it a single ipsilateral node that is 3 cm or less with extranodal (which would instead be categorized as N2a as above).

General Rules

  • Uses the Shared Nodal Staging System described previously.
  • If a patient has any clinical extranodal extension, they are automatically be categorized in the maximum possible N sub-category (N3b).
  • Pathologic N categorization is almost the same except for the isolated situation of having a single ipsilateral lymph node that is 3 cm or less with ENE identified only on pathology.
    • Instead of being up-categorized to N3b, this specific case is up-categorized to N2a instead.
    • In all other situations where there is ENE (clinical or pathologic), they are still up-categorized to N3b.
  • Clinically the AJCC defines ENE as invasion of skin, infiltration of musculature/fixation to adjacent structures on clinical examination, cranial nerve, brachial plexus, sympathetic trunk or phrenic nerve invasion with dysfunction.

Extranodal Extension (ENE)

  • Pathologically, ENE is defined as extension of metastatic tumour beyond the confines of the lymph node itself.
  • Clinically the AJCC defines ENE as invasion of skin, infiltration of musculature/fixation to adjacent structures on clinical examination, cranial nerve, brachial plexus, sympathetic trunk or phrenic nerve invasion with dysfunction.
M-Categorization
M Category Criteria
M0

No distant metastasis
M1

Distant metastasis present
Group Staging

Shared Group Staging System

N0
M0		 N1
M0		 N2
M0		 N3
M0		 Any N
M1
T1 I III IVA IVB IVC
T2 II III IVA IVB IVC
T3 III III IVA IVB IVC
T4a IVA IVA IVA IVB IVC
T4b IVB IVB IVB IVB IVC

General Rules

  • Uses the Shared Group Staging System described previously.
  • Straightforward to remember due to the pattern seen above when creating a table against the T and N staging.
  • (T1 N0) is staged as Stage I, and (T2, N0) is staged as Stage II. Thereafter, each increasing stage is immediately to the right and below the previous stage.
CHAPTER 6. Hypopharynx CHAPTER 8. Esophagus and Esophagogastric Junction