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 whether 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 most commonly used system to stage urethral cancer is the TNM system from the American Joint Committee on Cancer (AJCC). Ask your healthcare provider to explain the stage of your cancer in a way that you can understand.

The first step in staging is to find 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 layers of the urethra 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 bone.

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 (TX), or if the lymph nodes have cancer cells in them (NX).
• 0 means no sign of cancer, such as no sign of the main (primary) tumor (N0).

The grade of the cancer is a measure of how quickly the cancer is likely to grow and spread. It’s based on how the cancer cells look under the microscope. The urethral cancer cells are graded on a scale from 1 to 3. Lower grade cancers look more like normal cells. They are likely to grow and spread slowly. Higher grade cancers tend to grow and spread quickly.

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 of I through IV (1 through 4). The higher the number, the more advanced the cancer is.

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

Stage 0 . The cancer cells are only in the innermost lining of the urethra. Stage 0 is also called carcinoma in situ.

Stage I . The cancer cells have grown into the layer of tissue below the urethral lining. The cancer is only in the urethra.

Stage II . The cancer has spread into the deeper muscle layer of the urethra. In men, the tissue in the penis outside the urethra or the part of prostate gland surrounding the urethra may contain cancer cells. It has not spread to nearby lymph nodes or to organs in other parts of the body.

Stage III. One of the following is true:

• The cancer cells have grown into the layer of tissue below the urethral lining. Cancer is also found in 1 nearby lymph node. It has not spread to organs in other parts of the body.
• The cancer has spread through the wall of the urethra. In men, it has spread to the tissue in the penis outside the urethra or to the part of prostate gland surrounding the urethra. Cancer is also found in 1 nearby lymph node. It has not spread to organs in other parts of the body.
• The cancer has spread to tissues beyond the urethra. In women, it's spread to the vagina. In men, it's in the fatty tissue that surrounds the prostate or the deep tissues of the penis. It has not spread to nearby lymph nodes or to organs in other parts of the body.
• The cancer has spread to tissues beyond the urethra. In women, it's spread to the vagina. In men, it's in the fatty tissue that surrounds the prostate or the deep tissues of the penis. Cancer is also found in one nearby lymph node. It has not spread to organs in other parts of the body.

Stage IV . One of the following is true:

• The cancer has spread to the bladder, rectum, or prostate (in men). It has not spread to nearby lymph nodes or to organs in other parts of the body.
• The cancer has spread to the bladder, rectum, or prostate (in men). Cancer is also found in 1 nearby lymph node. It has not spread to organs in other parts of the body.
• The cancer may or may not have spread beyond the urethra to nearby tissues. It has spread to 2 or more nearby lymph nodes. It has not spread to organs in other parts of the body.
• The cancer has spread to distant lymph nodes or to organs in other parts of the body, such as a lung, the liver, or bones.

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.