Stages and grades of oropharyngeal cancer

T (tumour)

T describes the size of the tumour (area of cancer). 

TX

This means the main cancer (primary) can’t be assessed.

Tis

This means the cancer cells are in the top layer of cells lining the oropharynx.

T1 

This means the tumour is 2cm or smaller.

T2

This means the tumour is larger than 2cm, but no larger than 4cm.

T3

T3 means one of the following:

• the cancer is larger than 4cm

• the cancer has spread into the flap of tissue (epiglottis) at the top of the voice box (larynx)

T4 

This means the cancer has spread into nearby areas, such as the voice box (larynx), the tongue muscles, or bones, including the jawbone (mandible, hard palate or other bones, nearby muscle, the side of the nasopharynx, the base of the skull or has surrounded a large blood vessel called the carotid artery.

Node (N)

N refers to your lymph nodes. These are a network of glands throughout the body, for example in your armpits and neck. They drain away waste fluid, waste products and damaged cells, and contain cells that fight infection. 

When looking at your lymph nodes, your doctor keeps the following in mind:

• whether any nodes contain cancer

• the size of the node containing cancer

• which side of the neck the node containing cancer is in

NX

This means the lymph node can’t be assessed.

N0

This means the lymph nodes don’t contain cancer cells. 

N1

This means that one or more lymph node contains cancer cells on the same side of the neck as the cancer. None of the nodes are larger than 6cm.

N2 

This means there are cancer cells in lymph nodes on the opposite side of the neck to the cancer, or on both sides. None of these nodes is larger than 6cm.

N3 

This means at least one lymph node is bigger than 6cm.

Metastasis (M)

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

M0 

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

M1 

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

Stage 0 or carcinoma in situ (CIS)

Stage 0 cancer or carcinoma in situ (CIS) means your cancer is at a very early stage. Some doctors prefer to call this pre cancer. There are cancer cells, but they are all contained within the top layer of the lining of the oropharynx. The cancer cells have not spread.

If the pre cancer is not treated, there is a high risk the condition will develop into an invasive cancer.

In the TNM staging system stage 0 mouth cancer is the same as Tis, N0, M0.

Stage 1

The cancer is 4cm or smaller. The lymph nodes might contain cancer cells on the same side of the neck as the cancer. None of the nodes are larger than 6cm. 

In the TNM staging system stage 1 is the same as T1 - 2, N0 - 1, M0.

Stage 2

Stage 2 means one of the following:

• the cancer is 4cm or smaller and there are cancer cells in lymph nodes on the opposite side of the neck to the cancer, or on both sides, but none are larger than 6cm. It has not spread to other parts of the body

• the cancer is larger than 4cm, or the cancer has spread into nearby areas, such as the voice box (larynx), the tongue muscles, or bones including the jawbone (mandible), hard palate or other bones, nearby muscle, the side of the nasopharynx, the base of the skull or has surrounded a large blood vessel called the carotid artery, and the lymph nodes may contain cancer cells on the same side of the neck to the cancer, but none are larger than 6cm. It has not spread to other parts of the body

In the TNM staging system stage 2 is the same as one of the following:

• T1 - 2, N2, M0

• T3 - 4, N0,1, M0

Stage 3

Stage 3 means:

• the cancer is larger than 4cm, or the cancer has spread into nearby areas, such as the voice box (larynx), the tongue muscles, or bones including the jawbone (mandible), hard palate or other bones, nearby muscle, the side of the nasopharynx, the base of the skull or has surrounded a large blood vessel called the carotid artery. There are cancer cells in lymph nodes on the opposite side of the neck to the cancer, or on both sides. None of these nodes are larger than 6cm. It has not spread to other parts of the body

In the TNM staging system, stage 3 cancer is the same as one of the following:

• T3 - 4, N2, M0

Stage 4

Stage 4 means the cancer is advanced. The cancer has spread to other parts of the body, such as the lungs.

In the TNM staging system stage 4 cancer means any T, any N, M1.

The grade of a cancer tells you how much the cancer cells look like normal cells. Doctors don't grade HPV positive oropharyngeal cancers.

T (tumour)

T describes the size of the tumour (area of cancer). 

TX

This means the main cancer (primary) can’t be assessed. Tis means the cancer cells are in the top layer of cells lining the oropharynx.

T1 

This means the tumour is 2cm or smaller.

T2 

This means the tumour is larger than 2cm, but no larger than 4cm.

T3 

This can mean one of the following:

• the cancer is larger than 4cm

• the cancer has spread into the flap of tissue (epiglottis) at the top of the voice box (larynx)

T4

T4 is split into 2 groups - T4a and T4b.

T4a means the cancer has spread into nearby areas, such as the voice box (larynx), the tongue muscles, or bones, including the jawbone (mandible), hard palate or other bones. This is also called moderately advanced local disease.

T4b means the cancer has spread into nearby areas such as nearby bones, nearby muscle, the side of the nasopharynx, the base of the skull or has surrounded a large blood vessel called the carotid artery. This is also called very advanced local disease.

Node (N)

N refers to your lymph nodes. These are a network of glands throughout the body, for example, in your armpits and neck. They drain away waste fluid, waste products and damaged cells, and contain cells that fight infection. 

When looking at your lymph nodes, your doctor keeps the following in mind:

• whether any nodes contain cancer

• the size of the node containing cancer

• which side of the neck the node containing cancer is on

• whether the cancer has spread into the tissue surrounding a lymph node (extranodal extension or ENE)

NX

This means the lymph node can’t be assessed.

N0

This means the lymph nodes don’t contain cancer cells. 

N1 

This means that one lymph node contains cancer cells on the same side of the neck as the cancer. The node is no larger than 3cm across. The cancer has not spread into the tissue surrounding the lymph node.

N2

N2 is split into 3 groups - N2a, N2b and N2c:

N2a means one lymph node contains cancer cells on the same side of the neck as the cancer. The node is between 3 cm and 6 cm across. The cancer has not spread into the tissue surrounding the lymph node.

N2b means that more than one lymph node contains cancer cells on the same side of the neck as the cancer. None of these nodes are more than 6cm across. The cancer has not spread into the tissue surrounding the lymph node.

N2c means there are cancer cells in lymph nodes on the other side of the neck to the cancer, or in nodes on both sides of the neck. None of these nodes are more than 6cm across. The cancer has not spread into the tissue surrounding the lymph node.

N3

N3 is split into 2 groups - N3a and N3b:

N3a means that one lymph node containing cancer cells is larger than 6cm across. The cancer has not spread into the tissues surrounding the lymph node.

N3b means any number of lymph nodes contain cancer cells. The cancer has spread into the tissues surrounding a lymph node.

Metastasis (M)

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

M0 

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

M1 

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

Stage 0 or carcinoma in situ (CIS)

Stage 0 cancer or carcinoma in situ (CIS) means your cancer is at a very early stage. Some doctors prefer to call this pre cancer. There are cancer cells but they are all contained within the top layer of the lining of the oropharynx. The cancer cells have not spread.

If the pre cancer is not treated, there is a high risk the condition will develop into an invasive cancer.

In the TNM staging system stage 0 mouth cancer is the same as Tis, N0, M0.

Stage 1

This is the earliest stage of invasive cancer. 

It means the cancer is 2cm or smaller. It has not spread to nearby tissues, lymph nodes or other organs.

In the TNM staging system, stage 1 cancer is the same as T1, N0, M0.

Stage 2

Stage 2 means the cancer is larger than 2cm but no larger than 4cm. It has not spread to nearby lymph nodes or other organs.

In the TNM staging system, stage 2 cancer is the same as T2, N0, M0.

Stage 3

Stage 3 can mean one of the following:

• the cancer is larger than 4cm or has spread into the flap of tissue (epiglottis) at the top of the voice box (larynx), but it has not spread to any lymph nodes or to other parts of the body

• the cancer is any size, but one lymph node contains cancer cells on the same side of the neck as the cancer - the lymph node is no more than 3cm across, and it hasn't spread into the tissue surrounding the node or to other parts of the body

In the TNM staging system, stage 3 cancer is the same as one of the following:

• T3, N0, M0

• T1 - 3, N1, M0

Stage 4

Stage 4 means the cancer is advanced. It is further divided into 3 stages - 4a, 4b and 4c:

Stage 4a 

Stage 4a can mean  one of the following:

• the cancer is any size and has spread into one or more lymph nodes on the same side of the neck as the cancer, on the other side of the neck to the cancer or on both sides. The nodes are between 3 and 6 cm in size. It has not spread into the tissues surrounding the lymph nodes or other parts of the body

• the cancer has spread into nearby areas, such as the voice box (larynx), the tongue muscles, or bones, including the jawbone (mandible), hard palate or other bones. The cancer may have spread into one or more lymph nodes on the same side of the neck as the cancer, on the other side of the neck to the cancer or both sides. The nodes are between 3 and 6cm across. The cancer has not spread into the tissue surrounding a lymph node or other parts of the body

In the TNM staging system stage 4a cancer is the same as one of the following:

• T1 - 3, N2, M0

• T4a, N0 - 2, M0

Stage 4b

Stage 4b can mean one of the following:

• the cancer is any size, and one or more lymph nodes contain cancer cells and are larger than 6cm across. The cancer may have spread into the tissues surrounding the lymph node. It has not spread to other parts of the body

• the cancer has spread into nearby areas such as nearby bones, nearby muscle, the side of the nasopharynx, the base of the skull or has surrounded a large blood vessel called the carotid artery. The cancer may have spread into one or more lymph nodes on the same side of the neck as the cancer, on the other side of the neck to the cancer or both sides, a lymph node may be more than 6cm across, and the cancer may have spread into the tissues surrounding the lymph node. It has not spread to other parts of the body   

In the TNM staging system stage 4b cancer is the same as one of the following:

• any T, N3, M0

• T4b, any N, M0

Stage 4c

Stage 4c means the cancer has spread to other parts of the body, such as the lungs or bones.

In the TNM staging system, stage 4c cancer means:

• any T, any N, M1

The grade of a cancer tells you how much the cancer cells look like normal cells. This gives your doctor an idea of how the cancer might behave and what treatment you need. 

There are 4 grades of HPV negative oropharyngeal cancer:

• grade 1 (low grade) the cells look very much like normal oropharyngeal cells

• grade 2 (intermediate grade) the cells look slightly different to normal oropharyngeal cells

• grade 3 (high grade) the cells look very abnormal and not much like normal cells 

• grade 4 (high grade) the cells look very different to normal oropharyngeal cells

Differentiation means how developed or mature a cell is. Doctors might describe cancer as poorly or well differentiated. 

So doctors may describe:

• grade 1 cancer as well differentiated

• grade 2 cancer cells as moderately differentiated

• grade 3 cancer cells as poorly differentiated

• grade 4 cancer cells as undifferentiated

Your cancer might be graded as Gx. This means that they cannot assess the grade.