Staging bladder cancer is a way of describing where in the bladder that the cancer is located and whether it has spread (metastasized) to other parts of the body. Knowing the stage helps the doctor to decide what cancer treatment options are best for your specific case of bladder cancer. It can also help predict a patient's prognosis, which is the chance of recovery.
The most common tool doctors use to stage bladder cancer is the TNM system.
TNM stands for:
- T = Tumor size
- N = Lymph Node status (the number and location of lymph nodes with cancer)
- M = Metastases (whether or not the cancer has spread to other parts of the body)
T categories for bladder cancer
T followed by a number from 0 to 4 describes the main (primary) tumor's size and if it has spread. Higher T numbers mean a larger tumor and/or wider spread.
- TX: The primary tumor cannot be evaluated.
- T0: There is no evidence of a primary tumor in the bladder.
- Ta: A noninvasive papillary carcinoma, which is often found on a small section of tissue that easily can be removed
- Tis: Carcinoma in situ (CIS) or a "flat tumor," which means the cancer is only found on or near the surface of the bladder. This type of bladder cancer often comes back after treatment, usually as another noninvasive cancer in the bladder.
- T1: Tumor has spread to the connective tissue (called the lamina propria) that separates the lining of the bladder from the muscles beneath, but it does not involve the bladder wall muscle.
- T2: Tumor has spread to the muscle of the bladder wall.
- T2a: The tumor has spread to the inner half of the muscle of the bladder wall
- T2b: The tumor has spread to the deep muscle of the bladder (the outer half of the muscle)
- T3: Tumor has grown into the perivesical tissue (the fatty tissue that surrounds the bladder).
- T3a: The tumor has grown into the perivesical tissue, as seen through a microscope
- T3b: The tumor has grown into the perivesical tissue macroscopically, which means that the tumor(s) is large enough to be seen during imaging tests or to be seen or felt by the doctor
- T4: Tumor has spread to any of the following: the abdominal wall, the pelvic wall, a man's prostate or seminal vesicle (the tubes that carry semen), or a woman's uterus or vagina
- T4a: The tumor has spread to the prostate, seminal vesicles, uterus, or vagina
- T4b: The tumor has spread to the pelvic wall or the abdominal wall
N categories for bladder cancer
N followed by a number from 0 to 3 indicates whether the cancer has spread to lymph nodes.
- NX: Regional lymph nodes cannot be evaluated
- N0: Cancer has not spread to the regional lymph nodes
- N1: Cancer has spread to a single regional lymph node in the pelvis
- N2: Cancer has spread to 2 or more regional lymph nodes in the pelvis
- N3: Cancer has spread to the common iliac lymph nodes, which are located behind the major arteries in the pelvis, above the bladder
M categories for bladder cancer
M describes whether the cancer has spread to other parts of the body (called distant metastasis).
- M0: The disease has not metastasized
- M1: There is distant metastasis
- M1a: Cancer has spread only to lymph nodes outside of the pelvis
- M1b: Cancer has spread other parts of the body
Bladder Cancer Stage Grouping
The results are combined to determine the stage of bladder cancer for each person. There are 5 stages: stage 0 (zero) and stages I through IV (1 through 4).
- Stage 0, called Papillary Carcinoma and Carcinoma in Situ, is divided into stage 0a and stage 0is, depending on the type of the tumor:
- Stage 0a (papillary carcinoma): Abnormal cells are found in tissue lining the inside of the bladder. These abnormal cells, which may look like tiny mushrooms growing from the lining of the bladder, may become cancer and spread into nearby normal tissue (Ta, N0, M0).
- Stage 0is (carcinoma in situ): A flat tumor on the tissue lining the inside of the bladder. It has not grown in toward the hollow part of the bladder, and it has not spread to the thick layer of muscle or connective tissue of the bladder (Tis, N0, M0).
- Stage I: Cancer has formed and spread to the layer of tissue under the inner lining of the bladder. It has not spread to the thick layer of muscle in the bladder wall or to lymph nodes or other organs (T1, N0, M0).
- Stage II: Cancer has spread to either the inner half or outer half of the muscle wall of the bladder. The tumor has not reached the fatty tissue surrounding the bladder and has not spread to the lymph nodes or other organs (T2, N0, M0).
- Stage III: Cancer has spread from the bladder to the fatty layer of tissue surrounding it, and may have spread to the reproductive organs (prostate, uterus, vagina). The cancer may also have spread to the regional lymph nodes.
- Stage IIIA: Tumor has grown into the perivesical tissue or has spread to the prostate, uterus, or vagina, but has not spread to the lymph nodes or other organs (T3a, T3b, or T4a; N0; M0)
OR
Cancer has spread to a single regional lymph node (T1 to T4a, N1, M0) - Stage IIIB: The cancer has spread to 2 or more regional lymph nodes or to the common iliac lymph nodes (T1 to T4a, N2 or N3, M0).
- Stage IIIA: Tumor has grown into the perivesical tissue or has spread to the prostate, uterus, or vagina, but has not spread to the lymph nodes or other organs (T3a, T3b, or T4a; N0; M0)
- Stage IV: Cancer has spread from the bladder to the wall of the abdomen or pelvis and may also have spread to one or more lymph nodes or to other parts of the body.
- Stage IVA: Tumor has spread to the pelvic wall or the abdominal wall but not to other parts of the body (T4b, any N, M0)
OR
The cancer has spread to lymph nodes located outside of the pelvis (any T, any N, M1a) - Stage IVB: The cancer has spread other parts of the body (any T, any N, M1b).
- Stage IVA: Tumor has spread to the pelvic wall or the abdominal wall but not to other parts of the body (T4b, any N, M0)
