Staging for laryngeal cancer in the area below the vocal cords (subglottis)

There are different ways of staging cancer in the area below the vocal cords (subglottis) The 2 main ways are the TNM system and the number staging system. TNM stands for tumour, node and metastasis. 

You may not be familiar with these terms, but you can ask your doctor if you would like to know more.

Diagram of the larynx

TNM stages

Your doctor might use clinical or pathological staging to stage your cancer.

Clinical staging. Your doctor stages your cancer after examining you and looking at test and scan results. Doctors use clinical staging if you don’t have surgery straight away.
 
Pathological staging. Your doctor stages your cancer by using the tissue removed during the operation.
 
We have included clinical staging on this page. Staging in general can be quite complex. Speak to your doctor or specialist nurse for more information. They can help you understand more about your individual stage.

Tumour (T)

Tumour (T) describes the size of the tumour and how far it’s grown in the nearby area.

Tis

Tis means tumour in situ. The cancer is very early. It is in the top layer of cells that line the area below the vocal cords (subglottis) and has not spread into any surrounding tissue. 

T1

The cancer has grown deeper but is only in the subglottis.

T2

The cancer has grown from the subglottis into one or both vocal cords. The vocal cords may not be able to move as well as normal.

T3

T3 can mean the following. The cancer:

  • is still in the voice box (larynx) but has stopped a vocal cord from moving (your doctor may call this vocal cord fixation)
  • has grown into the inner part of the cartilage that protects the vocal cords (thyroid cartilage)

T4

T4 is divided into 2 stages:

T4a means one or all of the below. The cancer has grown:

  • through the cricoid cartilage or outer part of the thyroid cartilage
  • into the tissues outside the voice box such as the windpipe, soft tissues of the neck, deep muscles of the tongue, the thyroid gland or food pipe (oesophagus)

T4a cancer of the larynx is also called moderately advanced local disease.

T4b means:

  • the cancer has grown into the space before the spine (prevertebral space), around a blood vessel called the carotid artery, or into structures between the lungs (mediastinum)

T4b cancer of the larynx is also called advanced local disease.

Node (N)

Node (N) describes whether your cancer has spread to the lymph nodes.

When your doctor plans your treatment, it is important for them to know:

  • whether any nodes contain cancer
  • the size of the node containing cancer
  • which side of the neck the node containing cancer is on

N0 means there are no cancer cells in nearby lymph nodes.

N1 means there are cancer cells in one lymph node on the same side of the neck as the tumour. The node measures 3cm across or less.

N2 is split into 3 groups based on how many lymph nodes are affected, their size and if they are on the same side or both sides of the neck:

  • N2a means there are cancer cells in one lymph node, on the same side of the neck as the tumour. The node is between 3cm and 6cm in size
  • N2b means there are cancer cells in more than one lymph node on the same side of the neck, but none are more than 6cm in size
  • N2c means there are cancer cells in at least one lymph node on the other side of the neck (or on both sides), but none are more than 6cm in size

N3 is split into 2 groups based on the size of the lymph node and whether it has spread outside the lymph node:

  • N3a means that the cancer has spread to a lymph node and it is larger than 6 cm in size
  • N3b means the cancer has spread to a lymph node and then has grown outside of it

Metastasis (M)

Metastasis (M) describes whether the cancer has spread to a different part of the body.

M0 means the cancer has not spread to other parts of the body.

M1 means the cancer has spread to other parts of the body, such as the lungs. 

Number stages

The number staging system uses the TNM system to divide cancers into stages. Most types of cancer have 4 stages, numbered from 1 to 4.

Stage 1 (T1 N0 M0)

Stage 1 means the cancer is only in the area below the vocal cords (subglottis). The cancer has not spread to nearby tissues, lymph nodes or other parts of the body. 

Stage 2 (T2 N0 M0)

Stage 2 means the cancer has grown from the subglottis into one or both vocal cords. The vocal cords might not be able to move as well as normal. The cancer has not spread to lymph nodes or other parts of the body.

Stage 3 (T3 N0 M0) or (T1-T3 N1 M0)

Stage 3 cancer of the subglottis means the cancer is still within the voice box (larynx) but has stopped the vocal cords from moving. Or the cancer has grown into the inner part of the thyroid cartilage. The cancer has not spread to nearby lymph nodes or to other parts of the body.

OR stage 3 means the same as any of the above (stage 1 to 3), but it has spread to one lymph node on the same side of the neck as the tumour. It measures 3cm across or less. The cancer has not spread to other parts of the body.

Stage 4

Stage 4 cancer is divided into stage 4A, 4B and 4C.

Stage 4A (T4a N0, N1 M0) or (T1- T4a N2 M0)

Stage 4A means the cancer has spread through the thyroid or cricoid cartilage and might have spread into tissues outside the voice box. The cancer might have spread to one lymph node on the same side of the neck, which is not more than 3 cm. It has not spread to other parts of the body.

OR stage 4A means the cancer is in the subglottis, might have spread into the vocal cords and might have spread outside the voice box. The cancer has spread to one or more lymph nodes on one or both sides of the neck. None of the lymph nodes are more than 6 cm. The cancer has not spread to other parts of the body.

Stage 4B (T4b any N M0) or (any T N3 M0)

Stage 4B means the cancer has grown into the prevertebral space, around the carotid artery or the structures in the space between the lungs. The cancer might have spread to nearby lymph nodes. It has not spread to other parts of the body.

OR stage 4B means the cancer can be any size. The cancer has spread to at least one lymph node that is larger than 6 cm across. Or it has started to grow outside the lymph node. It has not spread to other parts of the body.

Stage 4C (any T any N M1)

Stage 4C means the cancer has spread to another part of the body such as the lungs.

  • AJCC Cancer Staging Manual (8th edition)
    American Joint Committee on Cancer
    Springer, 2017

  • Head and Neck Cancer: United Kingdom National Multidisciplinary Guidelines, Sixth edition
    J Homer and S C Winter
    The Journal of Laryngology & Otology, 2024. Volume 138, Number S1

  • Laryngeal cancer 

    BMJ Best Practice

    M Pierce

    Last reviewed: 24 Apr 2024 Last updated: 16 Apr 2024 (accessed July 2024)

Last reviewed: 
23 Jul 2024
Next review due: 
23 Jul 2027

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