Staging a cancer involves describing its size, where it is and whether it has spread. Knowing the stage of your cancer will help you and your doctor decide on the best treatment.
If you have surgery, your doctor will grade the cancer by looking at how normal or abnormal the cells look under a microscope. Grading the cancer can help to show how likely it is to spread and how quickly
TNM system
T (tumour) - how far the tumour has grown through the bowel wall
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T1 - the tumour is in the inner layer of the bowel
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T2 – the tumour has grown into the muscle layer of the bowel wall
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T3 – the tumour has grown into the outer lining of the bowel wall
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T4 – the tumour has grown through the outer lining of the bowel wall
N (nodes) - whether the cancer has spread to nearby lymph nodes
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N0 – no lymph nodes contain cancer cells
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N1 – cancer cells in up to three nearby lymph nodes
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N2 – cancer cells in four or more nearby lymph nodes
M (metastases) - whether the cancer has spread (metastasised) to other parts of the body
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M0 – the cancer hasn’t spread to other parts of the body
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M1 – the cancer has spread to other parts of the body, like the liver or lungs
For example your diagnosis may be 'T3N1M0'. This means the cancer has grown into the outer lining of the bowel to up to three nearby lymph nodes, but has not spread to other parts of the body.
Information retrieved from Bowel Cancer UK. 2020
Number staging
Information from the TNM staging report can be used to give a number stage between 1 and 4.
- Stage 1 – the cancer hasn't spread outside the bowel wall
- Stage 2 – the cancer has grown into or through the outer layer of the bowel wall
- Stage 3 – the cancer has spread to nearby lymph nodes
- Stage 4 – the cancer has spread to other parts of the body
The table below gives more detail on information from the TNM staging system are used to give a number stage.
