Bladder Cancer : Stages and Grades
TNM staging system
One tool that doctors use to describe the stage is the TNM system. Doctors use the results from diagnostic tests and scans to answer these questions:
- Tumor (T):How large is the primary tumor? Where is it located?
- Node (N):Has the tumor spread to the lymph nodes? If so, where and how many?
- Metastasis (M):Has the cancer spread to other parts of the body? If so, where and how much?
The results are combined to determine the stage of cancer for each person. There are 5 stages: stage 0 (zero) and stages I through IV (1 through 4). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.
Staging can be clinical or pathological. Clinical staging is based on the results of tests done before surgery, which may include physical examinations, imaging scans, and biopsies. Pathological staging is based on what is found during surgery, including the results of physical examinations, imaging scans, and biopsies. In general, pathological staging gives the health care team the most amount of information to make a prognosis.
Here are more details on each part of the TNM system for bladder cancer.
T categories for bladder cancer:
T describes how far the main (primary) tumor has grown through the bladder wall and whether it has grown into nearby tissues.
These measurements refer to the primary tumor.
- TX means the primary tumor cannot be assessed or information is not known.
- TO means no evidence of primary tumor.
- Ta indicates noninvasive papillary carcinoma.
- Tis indicatesnoninvasive flat carcinoma, also called flat carcinoma in situ. This means that the disease is still localized, or contained within the urothelium layer of the bladder wall. Cancer cells have not invaded the deeper layers of bladder wall tissue.
- T1 means the tumor has grown from the layer of cells lining the bladder into the connective tissue below. It has not grown into the muscle layer of the bladder.
- T2 means the tumor has grown into the muscle layer. T2 has two sub-categories:
- T2a means the tumor is in the inner half of the muscle layer.
- T2b means the tumor is in the outer half of the muscle layer.
- T3 means the tumor has grown through the muscle layer and into the surrounding fatty tissue. T3 has two sub-categories:
- T3a means this spread into the fatty tissue can only be seen with a microscope.
- T3b means this spread into the fatty tissue is large enough to be seen on imaging test or to be seen/felt by the surgeon.
- T4 means the tumor has spread into nearby organs or structures. It may be growing in the stroma (main tissue) of the prostate, the seminal vesicles, uterus, vagina, pelvic wall or abdominal wall.
N categories for bladder cancer:
N indicates any cancer spread to lymph nodes near the bladder. Lymph nodes are bean-sized collections of immune system cells, to which cancers often spread first.
- NX means nearby lymph nodes cannot be assessed or information is not known.
- N0 means the cancer has not spread to any nearby lymph nodes.
- N1 means the cancer has spread to one lymph node in the true pelvis.
- N2 means the cancer has spread to two or more lymph nodes in the true pelvis.
- N3 means the cancer has spread to lymph nodes that lie along the common iliac artery.
M categories for bladder cavity and oropharyngeal cancers:
M indicates if the cancer has spread (metastasized) to distant sites, such as other organs, like the lungs or liver, or lymph nodes that are not near the bladder.
- M0: no distant spread
- M1: the cancer has spread to distant sites outside the bladder region (for example, the lungs, liver or bones)
Once the categories have been assigned, the cancer is staged in one of the following ways:
Stage 0: The cancer has only grown into the center of your bladder. It hasn’t spread into the tissues or muscle of your bladder wall itself. It hasn’t spread to your lymph nodes or other organs, either.
Stage I: The cancer has grown through the inner lining of your bladder, but not the muscle of your bladder wall. Nor has it spread to your lymph nodes or distant organs.
Stage II: The cancer has grown through the connective tissue in your bladder and into the muscle layer of the bladder.
Stage III: Cancer is now in the layer of fatty tissue that surrounds your bladder. It may also be in your prostate, uterus, or vagina. But it hasn’t spread to nearby lymph nodes or to distant organs.
Stage IV (stage 4 bladder cancer): In stage IV bladder cancer, one of the following applies:
- Cancer has grown through the bladder wall and into the pelvic or abdominal wall, but it has not spread to lymph nodes or distant sites.
- Cancer has spread to nearby lymph nodes but not to distant sites.
- Cancer has spread to distant sites, such as bones, liver or lungs.