The stage of a cancer is how much and how far the cancer has spread in your body. Your healthcare provider uses exams and tests to find out the size of the cancer and where it is. He or she can also see if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.

The place where cancer starts is called the primary site. Bladder cancer can spread from the primary site to other parts of your body. Cancer that has spread is called metastatic cancer. When a cancer spreads, it’s said to have metastasized.

The most commonly used system to stage bladder cancer is the TNM system from the American Joint Committee on Cancer (AJCC). Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.

The first step is to decide the value for each part of the TNM system. Here's what the letters stand for in the TNM system:

• T tells how far the main tumor has spread into the lining of your bladder and nearby tissue.

• N tells if the lymph nodes in the area of the original tumor have cancer in them.

• M tells if the cancer has spread (metastasized) to distant organs in the body, such as the liver, lung, or the lining of your belly (abdomen).

Numbers or letters after T, N, and M provide more details about each of these factors. There are also 2 other values that can be assigned:

• X means the provider does not have enough information to tell the extent of the main tumor, or if the lymph nodes have cancer cells in them. This value is often used before surgery.

• 0 means no sign, such as no sign of lymph node spread (N0).

Stage groupings are determined by combining the T, N, and M values from the TNM system. These groupings give an overall description of your cancer. A stage grouping can have a value of 0 or of Roman numerals I through IV (1 through 4). The higher the number, the more advanced your cancer is.

These are the stage groupings of bladder cancer and what they mean:

Stage 0. This means either of the following:

• Stage 0a. The cancer cells are found only on the surface of the inner lining of the bladder and are growing toward the inside, hollow center of the bladder. This stage is also called noninvasive papillary carcinoma.

• Stage 0is. The cancer is only on the inner lining of the bladder. It's flat and not growing toward the center of the bladder. It may also be called flat carcinoma in situ.

Stage I . The cancer has grown deeper into the inner lining of the bladder. But it hasn't spread into the bladder muscle, the fatty tissue around the bladder, lymph nodes, or other parts of your body.

Stage II . The cancer has spread to the muscle layers of the wall of the bladder. It hasn't spread into the fatty tissue around the bladder, lymph nodes, or other parts of your body.

Stage III . This stage is divided into 2 groups:

• Stage IIIA is either of the following:

  • The cancer has grown through the muscular wall of the bladder and into the layer of fatty tissue surrounding the bladder. In men, cancer cells may have spread to the prostate gland. In women, the cancer may have spread to the uterus or vagina. The cancer has not spread to lymph nodes or other parts of the body.

  • The cancer has grown into the inner layers of the bladder wall, into the muscle layers of the bladder wall, into the fatty tissue around the bladder, or into the prostate (in men) or the uterus or vagina (in women). It also has spread to one nearby lymph node. It hasn't grown in the pelvic or belly (abdominal) wall or spread to distant organs.

• Stage IIIB . The cancer has grown into the inner layers of the bladder wall, into the muscle layers of the bladder wall, into the fatty tissue around the bladder, or into the prostate (in men) or the uterus or vagina (in women). It also has spread to 2 or more nearby lymph nodes or to lymph nodes along the iliac arteries. It hasn't grown into the pelvic or belly wall or spread to distant organs.

Stage IV. This stage is divided into 2 groups:

• Stage IVA is either of the following:

  • The cancer has grown through the bladder wall and spread to the wall of your belly or to the wall of your pelvis. It hasn't spread to nearby lymph nodes or distant organs.

  • The cancer may or may not have grown through the bladder wall and spread to nearby organs or nearby lymph nodes. It has spread to distant lymph nodes.

• Stage IVB . The cancer may or may not have grown through the bladder wall and spread to nearby organs or nearby lymph nodes. It has spread to distant organs, such as the lungs, bones, or liver.

Once your cancer is staged, talk with your healthcare provider about what the stage means for you. Ask any questions and talk about your concerns.