DIFFERENT WAYS OF STAGING CANCERS

There are different ways of staging cancers. The two main ways are the TNM system and number system.


TNM stages of mouth and oropharyngeal cancers

‘TNM’ stands for Tumour, Node and Metastasis. The system describes

* The size of a primary tumour (T)
* Whether the cancer has spread to the lymph nodes (N)
* Whether the cancer has spread to a different part of the body (M)

‘T’ stages of mouth cancer

There are 4 main 'T' stages of mouth and oropharyngeal cancer

* T1 means the tumour is contained within the tissue of the mouth or oropharynx and is no larger than 2cm (3/4 inch)
* T2 means the tumour is larger than 2cm, but smaller than 4cm (about 1 ½ inches)
* T3 means the tumour is bigger than 4cm
* T4 means the tumour has grown further than the mouth or oropharynx and into nearby body tissues such as bone, tissues of the neck, neck muscles, tongue, skin, sinuses or the voice box (larynx)

‘N’ stages of mouth cancer

There are 4 main lymph node stages in cancer of the mouth and oropharynx. One of these, stage N2, is broken down into 3 sub-stages. The important points here are whether there is cancer in any of the lymph nodes and if so, the size of the node and which side of the neck it is on.

* N0 means there are no cancer cells in the lymph nodes
* N1 means there are cancer cells in 1 lymph node on the same side of the neck as the cancer, but the node is less than 3cm across
* N2a means there is cancer in 1 lymph node on the same side of the neck, and the node is more than 3cm across but less than 6cm across
* N2b means there is cancer in more than 1 lymph node, but none of these nodes are more than 6cm across. All the affected nodes are on the same side of the neck as the cancer.
* N2c means there is cancer in nodes on the other side of the neck, or in nodes on both sides, but none of these nodes are more than 6cm across
* N3 means that at least 1 node containing cancer is more than 6cm across

‘M’ stages of mouth cancer

There are two stages to describe spread of cancer of the mouth and oropharynx to other parts of the body

* M0 means there is no cancer spread to other parts of the body
* M1 means the cancer has spread to other parts of the body, such as the lungs

Together, the T, N and M stages give a complete description of the stage of your cancer. For example, if you have a T2, N0, M0 cancer, you have a tumour larger than 2cm but not larger than 4cm. The lymph nodes are clear and there is no spread of your cancer to other parts of the body.

Number stages of mouth cancers

There are four main stages in this system – stages 1 to 4. Some doctors also refer to stage 0.

Stage 0 or carcinoma in situ (CIS)

If you have CIS or stage 0 cancer of the mouth, you have a very early stage cancer. Some doctors prefer to call this pre-cancer. There are cancer cells there. But they are all contained entirely within the lining of the mouth or oropharynx. So they have not spread. As the cells have not spread, this is not yet a true cancer. If the pre-cancer is not treated, there is a high chance of this condition going on to develop into an invasive cancer.

Stage 1
This is the earliest stage of invasive cancer. It means that cancer has begun to grow through the tissues lining the mouth and into the deeper tissues underneath. The cancer is no more than 2 cm across and has not spread to nearby tissues, lymph nodes or other organs.

Stage 2
If you have stage 2 mouth cancer, the tumour is larger than 2 cm across, but less than 4cm. The cancer has not spread to lymph nodes or any other organs.

Stage 3

Having stage 3 mouth cancer can mean one of two things. Either the cancer is bigger than 4cm but has not spread to any lymph nodes or other parts of the body. Or the tumour is any size but has spread to one lymph node on the same side of the neck as the cancer. In this case the lymph node involved is no more than 3cm across.

Stage 4

This means the cancer is advanced. Stage 4 can mean one of 3 things

* The cancer has grown through the tissues around the lips and mouth - lymph nodes in the area may or may not contain cancer cells
* The cancer is any size and has spread to more than 1 lymph node on the same side of the neck as the cancer, or to lymph nodes on both sides of the neck, or to any lymph node that is bigger than 6cm
* The cancer has spread to other parts of the body such as the lungs or bones

The different grades of mouth and oropharyngeal cancer

The grade of a cancer tells you what the cells look like under a microscope. ` They are 'graded' according to how normal or abnormal they appear. There are 4 grades of oral and oropharyngeal cancer cells

* Grade 1 (low grade) – the cancer cells look very much like normal mouth or oropharyngeal
* Grade 2 (intermediate grade) – the cancer cells look slightly like normal mouth or oropharyngeal cells
* Grade 3 (high grade) – the cancer cells look very abnormal and not much like normal mouth or oropharyngeal cells
* Grade 4 (high grade) - the cancer cells do not look anything like normal mouth or oropharyngeal cells

Differentiation means how developed or mature a cell is. So you may hear your doctor describe grade 1 cancer cells as 'well differentiated'. Grade 2 cancer cells are 'moderately differentiated'. Grade 3 cancer cells are 'poorly differentiated'.

The grade of the cancer gives your specialist a 'rule of thumb' as to how the cancer is likely to behave. Low grade cancers are usually slower growing and less likely to spread. High grade cancers are likely to be faster growing and more likely to spread. This is only a guide. Your specialist will consider all your test results when deciding which treatment options are best for you.