Stages of bladder cancer
The stage of a cancer means how big the cancer is and whether it has spread. Knowing the stage helps your doctor decide which treatment you need.
The tests you have to diagnose your bladder cancer help your doctor find out the stage.
The TNM staging system is the most common way that doctors stage bladder cancer. TNM stands for Tumour, Node, Metastasis.
Doctors may also use a number staging system, but this is less common for bladder cancer.
Your doctor may use other terms to describe your bladder cancer stage. These include:
- non muscle invasive bladder cancer
- invasive or muscle invasive bladder cancer
- metastatic bladder cancer
TNM staging
This is the most common way that doctors stage bladder cancer. TNM stands for Tumour, Node, Metastasis.
Tumour (T)
Tumour describes the size of the tumour.
There are several T stages:
CIS or Tis means very early, high grade cancer cells are only in the innermost layer of the bladder lining.
Ta means the cancer is just in the innermost layer of the bladder lining.
T1 means the cancer has started to grow into the connective tissue beneath the bladder lining.
T2 means the cancer has grown through the connective tissue into the muscle. It is divided into T2a and T2b.
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T2a means the cancer has grown into the superficial muscle
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T2b means the cancer has grown into the deeper muscle
T3 means the cancer has grown through the muscle into the fat layer. It is split into T3a and T3b.
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T3a means the cancer in the fat layer can only be seen under a microscope (microscopic invasion)
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T3b means the cancer in the fat layer can be seen on tests, or felt by your doctor during an examination under anaesthetic (macroscopic invasion)
T4 means the cancer has spread outside the bladder. It is split into T4a and T4b.
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T4a means the cancer has spread to the prostate, womb (uterus) or vagina
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T4b means the cancer has spread to the wall of the pelvis or tummy (abdomen)
Node (N)
Node in TNM means your lymph nodes. These are a network of glands throughout the body, for example in your armpits, neck and groin. They drain away waste fluid, waste products and damaged cells, and contain cells that fight infection.
Cancer cells can enter the lymphatic system and travel around the body.
There are 4 lymph node (N) stages in bladder cancer - N0 to N3:
- N0 means there are no cancer cells in any lymph nodes
- N1 means there are cancer cells in one lymph node in the pelvis (between your hip bones)
- N2 means there are cancer cells in more than one lymph node in the pelvis
- N3 means there are cancer cells in one or more lymph node just outside the pelvis
Your doctor may call your cancer 'locally advanced bladder cancer' if it has spread to nearby lymph nodes (stages N1-3).
Metastasis (M)
Metastasis describes whether the cancer has spread to a different part of the body.
There are 2 M stages:
- M0 means your cancer has not spread to other parts of the body
- M1 means your cancer has spread to other parts of the body
M1 can be divided into M1a and M1b:
- M1a means your cancer has spread to the lymph nodes outside the pelvis
- M1b means your cancer has spread to other parts of the body like the bones, lungs and liver
Cancer that has spread to other areas of the body, such as the lungs, is called advanced or metastatic bladder cancer.
Number stages
There is another staging system for bladder cancer which is not used often. It has 5 main stages, numbered from stage 0 to stage 4. Stage 0 is the earliest cancer and stage 4 is the most advanced.
Stage 0
The cancer is just in the inner layer of the bladder lining (stage 0a) OR there are very early, high grade cancer cells only in the inner layer of the bladder lining (stage 0is).
Stage 1
The cancer has started to grow into the connective tissue beneath the bladder lining.
Stage 2
The cancer has grown through the connective tissue layer into the muscle of the bladder wall.
Stage 3
The cancer has grown through the muscle into the fat layer and may have spread to the prostate, womb or vagina. It might also have spread to nearby lymph nodes.
Stage 4
The cancer has spread to the wall of the tummy (abdomen) or between the hips (pelvis), to distant lymph nodes or to other parts of the body such as the bones, lungs or liver.
Other ways of describing bladder cancer stages
Your doctor might use the following terms to describe your bladder cancer stage:
Non muscle invasive bladder cancer
This means the cancer cells are only in the inner lining of the bladder. They have not grown through the inner lining and into the deeper muscle layer of the bladder. It is early in its development.
Muscle invasive bladder cancer
This means the cancer has spread into or through the muscle layer of the bladder.
Metastatic bladder cancer
Metastatic bladder cancer means the cancer has spread from the bladder to other parts of the body. It is also called advanced cancer. Bladder cancer might spread to lymph nodes in other parts of the body or to the bones, liver or lungs.