How is penile cancer staged?

Staging is the process of finding out how far a cancer has spread. Once penile cancer is diagnosed, your doctor will determine the stage of the cancer using the results of exams, biopsies, and any imaging tests you have had. (These were described in the section called "How is penile cancer diagnosed?") The stage of your cancer is a very important factor in planning your treatment and estimating your prognosis (outlook).

The stage of a cancer does not change over time, even if the cancer progresses. A cancer that comes back or spreads is still referred to by the stage it was given when it was first found and diagnosed, only information about the current extent of the cancer is added. A person keeps the same diagnosis stage, but more information is added to the diagnosis to explain the current disease status

If you have penile cancer, ask your cancer care team to explain staging in a way that you can understand. Knowing all you can about staging will let you take a more active role in making informed decisions about your treatment.

The American Joint Committee on Cancer (AJCC) TNM system

A staging system is a standardized way for the cancer care team to summarize information about how far a cancer has spread. The most common system used to describe the stages of squamous cell penile cancers is the American Joint Committee on Cancer (AJCC) TNM system. This system is based on 3 key pieces of information:

• T stands for tumor (how far it has spread within the penis and to nearby organs).
• N stands for spread to nearby lymph nodes (bean-sized collections of immune system cells that help fight infections and cancers).
• M is for metastasis (spread to distant organs).

Additional letters or numbers appear after T, N, and M to provide more details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means "cannot be assessed because the information is not available." The letters "is" after the T stand for "in situ," which means the cancer is only in the top layers of skin and has not yet invaded (grown into) a deeper layer of tissue. The type of staging described here is known as surgical or pathologic staging. This type of staging is based on the results of biopsies and the findings at surgery. Penile cancer can also be clinically staged. Clinical staging is based on the results of a physical exam and imaging studies (such as CT scans).

Another factor that can affect staging is the grade of the cancer. The grade is a measure of how abnormal the cancer cells appear when they are examined under a microscope. The grade can be expressed as a number, from 1 to 4. The higher the number, the more abnormal the cells look. Higher grade cancers tend to grow and spread more quickly than lower grade cancers.

T categories:

TX: Primary tumor cannot be assessed

T0: No evidence of primary tumor

Tis: Carcinoma in situ (cancer that is only in the top layers of skin)

Ta: Verrucous (wart-like) carcinoma that is only in the top layers of skin

T1: Tumor has grown into the tissue below the top layers of skin (called the subepithelial connective tissue)

• T1a: The cancer has grown into the subepithelial connective tissue, but it has not grown into blood or lymph vessels. The cancer is grade 1 or 2.
• T1b: The cancer has grown into the subepithelial connective tissue and either it has grown into blood and lymph vessels OR it is high-grade (grade 3 or 4).

T2: Tumor has grown into one of the internal chambers of the penis (the corpus spongiosum or corpora cavernosum)

T3: Tumor has grown into the urethra (the tube that carries urine and semen outside of the (body)

T4: Tumor has grown into the prostate or other nearby structures

N categories

NX: Nearby lymph nodes cannot be assessed

N0: No spread to nearby lymph nodes

N1: The cancer has spread to a single lymph node in the groin (inguinal lymph node)

N2: The cancer has spread to more than 1 inguinal lymph node

N3: The cancer has spread to lymph nodes in the pelvis and/or the cancer in the lymph nodes has grown through the outer covering of the lymph node and into the surrounding tissue

M categories

M0: The cancer has not spread to distant organs or tissues

M1: The cancer has spread to distant organs or tissues (such as lymph nodes outside of the pelvis, lungs, or liver)

Using the TNM system, a doctor might describe one case of penile cancer as T2, N0, M0 and another as T4, N1, M0.

Stage groupings

To summarize this information, TNM combinations are grouped together into a simpler set of stages, labeled stage 0 through stage IV. This is known as stage grouping.

Stage 0: Tis or Ta, N0, M0:

The cancer has not grown into tissue below the top layers of skin and has not spread to lymph nodes or distant sites.

Stage I: T1a, N0, M0:

The cancer has grown into tissue just below the superficial layer of skin but has not grown into blood or lymph vessels. It is a grade 1 or 2. It has not spread to lymph nodes or distant sites.

Stage II: Any of the following:

T1b, N0, M0: The cancer has grown into tissue just below the superficial layer of skin and is either high-grade or has grown into blood or lymph vessels. It has not spread to lymph nodes or distant sites

OR

T2, N0, M0: The cancer has grown into one of the internal chambers of the penis (the corpus spongiosum or corpora cavernosum). The cancer has not spread to lymph nodes or distant sites.

OR

T3, N0, M0: The cancer has grown into the urethra. It has not spread to lymph nodes or distant sites.

Stage IIIa: T1 to T3, N1, M0:

The cancer has grown into tissue below the superficial layer of skin (T1). It may also have grown into the corpus spongiosum, the corpus cavernosum, or the urethra (T2 or T3). The cancer has spread to a single groin lymph node (N1). It has not spread to distant sites.

Stage IIIb: T1 to T3, N2, M0:

The cancer has grown into the tissues of the penis and may have grown into the corpus spongiosum, the corpus cavernosum, or the urethra (T1 to T3). It has spread to 2 or more groin lymph nodes. It has not spread to distant sites

Stage IV: Any of the following:

T4, any N, M0: The cancer has grown into the prostate or other nearby structures. It may or may not have spread to groin lymph nodes. It has not spread to distant sites.

OR

Any T, N3, M0: The cancer has spread to lymph nodes in the pelvis OR the cancer spread in the groin lymph nodes has grown through the lymph nodes' outer covering and into the surrounding tissue. The cancer has not spread to distant sites.

OR

Any T, any N, M1: the cancer has spread to distant sites.

Recurrent cancer

Recurrent disease means that the cancer went away with treatment, but then later came back. Recurrent penile cancer may return in the penis or in any other part of the body. This isn't a formal stage of the TNM system, but a doctor may note it by putting a small 'r' in front of the stage (for example, rT2N1M0).