Staging and grading of bladder cancer
The TNM staging system uses letters and numbers to describe the bladder cancer.
Non-muscle-invasive bladder cancer means the cancer cells are only in the inner lining of the bladder. This means non-muscle-invasive bladder cancers are always N0 and M0.
Non-muscle-invasive bladder cancer can be staged as CIS, Ta or T1.
Carcinoma in situ (CIS)
The tumour has started to grow into the layer of connective tissue, beneath the bladder lining.
Some people may have both papillary cancer and CIS.
Muscle-invasive and advanced bladder cancer is staged as T2 to T4 . Your doctor or specialist nurse can tell you more about the stage of the bladder cancer you have.
T - the tumour
- T2 tumours have grown into the muscle of the bladder wall.
- T3 tumours have grown through the muscle of the bladder and into the fatty tissue around the bladder.
- T4 tumours have spread to other parts of the body near the bladder or in the pelvis.
N - the lymph nodes
- N0 means there is no cancer in the lymph nodes.
- N1 means the cancer is in one of the lymph nodes in the pelvis, near the bladder.
- N2 means the cancer is in more than one lymph node in the pelvis.
- N3 means there is cancer in one or more of the lymph nodes further away from the bladder but in the tummy (abdomen).
M - Metastasis
- M0 means the cancer has not spread to other parts of the body.
- M1 means the cancer has spread to other parts of the body, such as the bones, lungs, liver, or lymph nodes outside the tummy.
Doctors may use other terms to describe the stage of bladder cancer:
The cancer is in the muscle layer of the bladder or has spread into the fat layer. But it has not spread outside the bladder.
This is when the cancer has spread outside the bladder into nearby tissues, such as the prostate, vagina, ovaries, womb or back passage (rectum). It may also be in a lymph node in the pelvis, near to the bladder.
This is when the cancer has spread to other parts of the body, such as the liver, lungs or bones, or to the lymph nodes further from the bladder.
Grading is about how the cancer cells look under a microscope compared with normal cells. With muscle-invasive or advanced bladder cancer grading does not affect your treatment. With non-muscle-invasive bladder cancer grading is one of the things that helps your doctor plan your treatment.
The grades for bladder cancer are:
- grade 1 – the cancer cells look very similar to normal bladder cells, they are usually slow-growing and are less likely to spread
- grade 2 – the cancer cells look less like normal cells and are slightly faster growing
- grade 3 – the cancer cells look very different to normal cells and usually grow more quickly.
Your doctor may combine the stage and grade of the tumour when talking about your results. For example, they may say you have a TaG1, which is a stage Ta tumour and a grade 1 tumour.
Doctors may also use another grading system for bladder cancer:
- low-grade – the cancer cells are slow-growing and are less likely to spread
- high-grade – the cancer cells grow more quickly and are more likely to spread. Carcinoma in situ (CIS) is always classed as high-grade.
Your doctor may combine the two grading systems.