Bladder Cancer Stages / Staging

Bladder cancer staging is the process used to determine how much the cancer has spread. Your prognosis depends largely on the stage of cancer, which plays a key role in determining the appropriate treatment plan for you.

The TNM System 

The American Joint Committee on Cancer (AJCC) developed the TNM system to evaluate three primary factors when it comes to treating cancer:

• Tumor (T) describes the size of the original tumor, including whether it has grown through the bladder wall or invaded nearby tissues.
• Node (N) indicates whether the cancer is present in the lymph nodes.
• Metastasis (M) indicates whether the cancer has spread (metastasized) to other parts of the body.

A number (0-4) or the letter X is assigned to each factor. A higher number indicates increasing severity. For instance, a T1 score indicates a smaller tumor than a T2 score. The letter X means the information could not be assessed.

Once the T, N and M scores have been assigned, an overall bladder cancer stage is assigned.

T Categories for Bladder Cancer 

These measurements refer to the primary tumor.

• TX: primary tumor cannot be assessed; information not known
• TO: no evidence of primary tumor
• Ta: noninvasive papillary carcinoma
• Tis: noninvasive 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: 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: tumor has grown into the muscle layer
  • T2a: the tumor is in the inner half of the muscle layer
  • T2b: the tumor is in the outer half of the muscle layer
• T3: tumor has grown through the muscle layer and into the surrounding fatty tissue
  • T3a: this spread into the fatty tissue can only be seen with a microscope
  • T3b: this spread into the fatty tissue is large enough to be seen on imaging test or to be seen/felt by the surgeon
• T4: 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 

• NX: nearby lymph nodes cannot be assessed; information not known
• N0: the cancer has not spread to any nearby lymph nodes
• N1: the cancer has spread to one lymph node in the true pelvis
• N2: the cancer has spread to two or more lymph nodes in the true pelvis
• N3: the cancer has spread to lymph nodes that lie along the common iliac artery

M Categories for Bladder Cavity and Oropharyngeal Cancers 

• M0: no distant spread
• M1: the cancer has spread to distant sites outside the bladder region (for example, the lungs, liver or bones)

Bladder Cancer Stages 

Bladder cancer is classified as stage 0, I, II, III or IV according to the TNM measurements. Your doctor will assign a stage to the disease based upon this information, and will work with you to create a treatment plan.

Stage 0a: Ta, N0, M0 Bladder cancer is noninvasive papillary carcinoma. Cancer has grown toward the hollow center of the bladder but not into the connective tissue or muscle layer. There are no malignant cells in the lymph nodes or distant sites.

Stage 0is: Tis, N0, M0 Flat, noninvasive carcinoma, or carcinoma in situ. In this stage of bladder cancer, the tumor is growing only in the inner lining layer of the bladder. It has not grown toward the hollow part of the bladder, and has not invaded the connective tissue or muscle of the bladder wall. There are no malignant cells in the lymph nodes or distant sites.

Stage I: T1, N0, M0 Cancer has grown into the layer of connective tissue beneath the lining layer of the bladder wall. The disease has not spread to lymph nodes or distant sites.

Stage II: T2a or T2b, N0, M0 Cancer has grown into the muscle layer of the bladder wall. It has not grown through the muscle layer into the fatty tissue surrounding the bladder. In this bladder cancer stage, the disease has not spread to lymph nodes or distant sites.

Stage III: T3a, T3b, or T4a, N0, M0 Cancer has grown through the bladder wall into the surrounding fatty tissue (T3). It may also be present in the prostate, uterus or vagina (T4a). In this stage of bladder cancer is not present in the pelvic or abdominal wall, and has not spread to lymph nodes or distant sites.

Stage IV: One of the following applies –

• T4b, N0, M0: Cancer has grown through the bladder wall and into the pelvic or abdominal wall (T4b), but has not spread to lymph nodes or distant sites.

• Any T, N1 to N3, M0: Cancer has spread to nearby lymph nodes (N1–N3) but not to distant sites.
• Any T, any N, M1: Cancer has spread to distant sites, such as bones, liver, or lungs (M1).

Next Topic: Bladder Cancer Treatment