Identifying a cancer’s stage is a vital part of the diagnostic process. Staging will classify the cancer based on how large it is and where it was when first diagnosed. Information from diagnostic tests (see Diagnosis) can determine the size of the tumour, which parts of the bladder it is affecting, and whether it has spread from its original location. The stage of your cancer will be used by your healthcare team to determine an appropriate treatment plan and estimate prognosis for your case.
Bladder cancer is often staged according to the TNM system (1):
T describes how far the primary tumor has grown through the bladder wall and whether it has grown into nearby tissues.
N indicates cancer spread to lymph nodes near the bladder. Lymph nodes are collections of immune system cells, to which cancers often spread first.
M indicates if the cancer has metastasized to distant sites, such as other organs, like the lungs or liver, or lymph nodes that are not near the bladder.
There are 5 stages in bladder cancer, from 0 to 4. In general, a higher stage number indicates more cancer spreading. When describing the stage, you may hear doctors use the words local, regional or distant. Local means that the cancer is only in the bladder and has not spread to other parts of the body. Regional means close to the bladder or around it. Distant means in a part of the body farther from the bladder.
- Stage 0: the tumour is only in the lining of the bladder.
- Stage 0A is also referred to as non-invasive papillary carcinoma. In this case, the tumour has the appearance of a mushroom.
- Stage 0is is also called carcinoma in situ. This tumour is flat.
- Stage I: the tumour has grown into the connective tissue layer of the bladder.
- Stage II: the tumour has extended to the muscle layer of the bladder.
- Stage III: the tumour has spread outside of the bladder.
- Stage 3A means the tumour has grown into nearby tissues outside of the bladder, but not into the pelvic or abdominal walls.
- Stage 3B indicates that the tumour has spread to 1 lymph node in the pelvis.
- Stage IV: the tumour has spread farther from the bladder.
- Stage 4A: the tumour has grown into the pelvic or abdominal walls, or has spread to lymph nodes farther from the bladder.
- Stage 4B: the cancer has spread to other parts of the body (distant metastasis), such as the lungs, liver, or bone. This is also referred to as metastatic bladder cancer.
In cases of recurrent cancer, if the cancer is in the same place it originally occurred, this will be called local recurrence. If the cancer comes back in tissues or lymph nodes near the original site, it will be referred to as regional recurrence. If the cancer recurs in an entirely different part of the body, it will be called distant metastasis or distant recurrence.
Information taken from Canadian Cancer Society unless otherwise indicated.
(1) “Bladder Cancer Stages”, American Cancer Society, 2019. https://www.cancer.org/cancer/bladder-cancer/detection-diagnosis-staging/staging.html