Oropharyngeal cancer starts inthe oropharynx, whichis the partof the throat just behind the mouth.It includes cancer that starts in the back of the tongue and tonsil cancer.
The stage of your oropharyngealcancer tells you how big it is and whether it has spread. The grade means how abnormal the cancer cells look under the microscope.
Some oropharyngeal cancers contain a virus called HPV. Doctors stage oropharyngeal cancerthat containsHPV in a different way to oropharyngeal cancers that don't contain HPV.
Staging for oropharyngealcancer is different from that of cancers that start in the mouth.
- Find out about staging mouth cancer
Staging systems
Doctors use different systemsto stage oropharyngeal cancer.
Your doctor mightuse the TNM system. This system describes:
- the sizeof the primary tumour (T)
- whether the cancer has spread to thelymph nodes(N)
- whether the cancer has spread to anotherpart of the body (M)
Or the doctors mightuse a number staging system.The Number staging system divides oropharyngeal cancer into 4 main stages, from 1 to 4. Stage 1 is an early cancer and stage 4 is an advanced cancer. Some doctors also use stage 0.
Staging and human papillomavirus (HPV)
The doctor tests oropharyngeal cancer cells for a virus called human papillomavirus (HPV):
- HPV positive cancers contain HPV
- HPV negative cancers don’t contain HPV
People with HPV positive oropharyngeal cancers tend to have a better outlook than people with HPV negative oropharyngeal cancers. The way doctors stage HPV positive oropharyngeal cancers is different to how they stage HPV negative oropharyngeal cancers.
How do doctors find out your stage?
There are different ways to find out your stage. Your doctor might use:
- clinical stagingbefore treatment and if youdon't have surgery
- pathological stagingif youdo have surgery
Clinical stagingmeansthe doctor stages you after examining you and looking at test and scan results. Doctors use clinical staging to plan your treatment. It’s also the best way to stage people who aren’t having surgery. You might see your clinical stage written as cTNM.
Pathological stagingmeansthe doctorstages you after examining the tissue that the surgeon removes during an operation. This is also called surgical staging. The doctors combine your clinical stage results with the surgical results. Pathological staging is generally a more precise way to find out how far your cancer has spread. Your pathological stage might be different to your clinical stage. You might see your pathological stage written as pTNM.
Pathological staging is different from clinical staging for oropharyngeal cancer. For example, pathological staging looks at how many lymph nodes contain cancer, rather than the size of the lymph nodes.
In the sections below, we describe theclinical stage. This is because not everyone with oropharyngeal cancer has surgery to stage their cancer, so doctors don't always know the pathological stage.
Cancer staging is complicated, so if you need help understanding it, ask your doctor or specialist nurse to explain it to you.
You can call the Cancer Research UK nurses on freephone 0808 800 4040, from 9am to 5pm, Monday to Friday.
Staging and grading HPV positive oropharyngeal cancer
HPV positive oropharyngeal cancers contain the human papillomavirus(HPV). Your doctor might describe your cancer stage using the TNM staging system or the number staging system.
TNM staging
T (tumour)
T describes the size of the tumour (area of cancer).
TX means the main cancer (primary) can’t be assessed.
Tis means the cancer cells are in the top layer of cells lining the oropharynx.
T1means the tumour is2cm or smaller.
T2means the tumour is larger than 2cm, but no larger than 4cm.
T3means 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)
T4means 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)
Nrefers toyour lymph nodes. Theseare a network of glands throughout the body,for examplein your armpits andneck.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 means the lymph node can’t be assessed.
N0means the lymph nodes don’t contain cancer cells.
N1means that one or more lymph node contains cancer cellson the same side of the neck as the cancer.None of the nodes arelarger than 6cm.
N2means 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.
N3means at least onelymph node is bigger than 6cm.
Metastasis (M)
M describes whether the cancer has spread to a different part of the body.
M0means the cancer has not spread to other parts of the body.
M1means cancer has spread to other parts of the body, such as the lungs.
Number staging
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 nodesmight containcancer cellson the same side of the neck as the cancer.None of the nodes arelarger than 6cm.
In the TNM staging system stage 1is the same as T1 - 2, N0 - 1, M0.
Stage 2
Stage 2 meansoneof the following:
- the cancer is 4cm or smallerand there are cancer cells in lymph nodes on the opposite side of the neck to the cancer, or on both sides, but noneare 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 2is 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 3cancer 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.
Grading
The grade of a cancer tells you how much the cancer cells look like normal cells.Doctors don't grade HPV positive oropharyngeal cancers.
Staging and grading HPV negative oropharyngeal cancer
HPV negative oropharyngeal cancers do not contain the human papilloma virus(HPV). Your doctor might describe your cancer stage using the TNM staging system or the number staging system.
TNM staging
T (tumour)
T describes the size of the tumour (area of cancer).
TX means the main cancer (primary) can’t be assessed. Tismeans the cancer cells are in the top layer of cells lining the oropharynx.
T1means the tumour is2cm or smaller.
T2means the tumour is larger than 2cm, but no larger than 4cm.
T3can 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)
T4is split into 2 groups - T4a and T4b.
T4ameans 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.
T4bmeansthe 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)
Nrefers toyour lymph nodes. Theseare a network of glands throughout the body,for example, in your armpits andneck.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 means the lymph node can’t be assessed.
N0means the lymph nodes don’t contain cancer cells.
N1means that one lymph node contains cancer cells on the same side of the neck as the cancer. The node isno larger than 3cm across. The cancerhas notspread into the tissue surrounding the lymph node.
N2is split into 3 groups - N2a, N2b and N2c:
N2ameansone lymph node contains cancer cells on the same side of the neck as the cancer. Thenode is between 3 cm and 6 cm across. The cancerhas notspread into the tissue surrounding the lymph node.
N2bmeans 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 cancerhas notspread into the tissue surrounding the lymph node.
N2cmeans 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 cancerhas notspread into the tissue surrounding the lymph node.
N3is split into 2 groups - N3a and N3b:
N3ameans that one lymph node containingcancer cellsis larger than 6cm across. The cancerhas notspread into the tissues surrounding the lymph node.
N3bmeans any number oflymph nodes containcancer 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.
M0means the cancer has not spread to other parts of the body.
M1means cancer has spread to other parts of the body, such as the lungs.
Number staging
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 1cancer is the same as T1, N0, M0.
Stage 2
Stage 2 means the cancer is larger than 2cmbutno larger than 4cm.It has not spread to nearby lymph nodes or other organs.
In the TNM staging system, stage 2cancer is the same as T2, N0, M0.
Stage 3
Stage 3 can mean oneof the following:
- the cancer is larger than 4cmor 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 canceris any size, butone 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 4acancer 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 4cmeans 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
Grading
The grade of a cancer tells you how much the cancer cells look like normal cells. Thisgives your doctor an idea of how the cancer might behave and what treatment you need.
There are 4grades of HPV negative oropharyngeal cancer:
- grade 1 (low grade) the cells look very much like normaloropharyngeal 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 normaloropharyngeal 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 canceras 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.
Treatment
The stage of your cancer helps your doctor to decide whichtreatment you need. Treatment also depends on:
- your type of cancer (the type of cells the cancer started in)
- where the cancer is
- other health conditions that you have
The stage of the cancer and these other factors can also give an idea of your outlook (prognosis).
Treatment mightinclude:
surgery 
radiotherapy as the main (primary) treatment- radiotherapy on its own or with
chemotherapy (chemoradiotherapy ) after surgery - chemotherapy
- a
targeted drug immunotherapy
- Find out about treatment
