ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.
Grading and staging are ways of describing how fast-growing the cancer is and how much it has grown, including where the cancer is located and if or where it has spread. Doctors use diagnostic tests to find out the cancer's grade and stage, so grading and staging may not be complete until all the tests are finished. Knowing the grade and stage helps the doctor to decide what kind of treatment is best and helps predict a patient's prognosis, which is the chance of recovery. A lower grade or stage cancer is associated with a better chance of recovery than a higher grade or stage cancer.
One way doctors describe penile cancer is by grade (G), which describes how much the cancer cells look like healthy cells when viewed under a microscope. The doctor compares the cancerous tissue with healthy tissue. Healthy tissue usually contains many different types of cells grouped together. If the cancer looks similar to healthy tissue and contains different cell groupings, it is called differentiated or a low-grade tumor. If the cancerous tissue looks very different from healthy tissue, it is called poorly differentiated or a high-grade tumor. The cancer’s grade can help the doctor predict how quickly the cancer will spread.
GX: The tumor grade cannot be identified.
G1: Describes cells that look more like normal tissue cells, called well differentiated.
G2: The cells are somewhat different from normal cells, called moderately differentiated.
G3: Describes tumor cells that look very much like each other, but do not look very much like normal cells, called poorly differentiated.
G4: The tumor cells barely look like normal cells, called undifferentiated.
There are different stage descriptions for different types of cancer. One tool that doctors use to describe the stage is the TNM system. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
- How large is the primary tumor, where is it located, and what is the grade of the tumor (see Grades above)? (Tumor, T)
- Has the tumor spread to the lymph nodes near the tumor? (Node, N)
- Has the cancer metastasized (spread) to other parts of the body? (Metastasis, M)
The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments.
Here are more details on each part of the TNM system for penile cancer:
Tumor. Using the TNM system, the "T" plus a letter and/or number (zero to four) is used to describe the size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. This helps the doctor develop the best treatment plan for each patient. Specific tumor stage information is listed below:
TX: The primary tumor cannot be evaluated.
T0: There is no tumor.
Tis: An early, noninvasive precancerous growth. This is also called carcinoma in situ.
Ta: The tumor is a noninvasive, wart-like carcinoma, which looks somewhat like a small piece of broccoli or cabbage.
T1a: The tumor has invaded into the subepithelial connective tissue, which is tissue below the top layers of skin. The tumor has not grown into blood or lymph vessels, and the tumor grade (see above) is G2 or lower.
T1b: The tumor has grown into the subepithelial connective tissue. The tumor has grown into blood or lymph vessels, and/or the tumor grading is G3 or higher.
T2: The tumor has grown into the corpus spongiosum or corpora cavernosum, which are internal chambers of the penis.
T3: The tumor has grown into the urethra.
T4: The tumor has grown into other nearby structures such as the pubic bone, the scrotum, or the prostate.
Node. The “N” in the TNM staging system stands for lymph nodes near the cancer, called regional lymph nodes. The regional lymph nodes for penile cancer are located in the groin and the pelvis. Lymph nodes in other parts of the body are called distant lymph nodes. Staging places cancers that have spread to regional lymph nodes and cancers that have spread to distant lymph nodes in separate categories. The N in TNM staging only refers to the regional lymph nodes.
If the doctor evaluates the lymph nodes before the biopsy or surgery, based on a physical examination and/or other tests, the letter “c”, for “clinical” staging, is placed in front of the N. If the doctor evaluates the lymph nodes after a biopsy or surgical removal of the lymph nodes, which is more accurate, the letter “p”, for “pathologic” staging, is placed in front of the N. The information below describes the pathologic staging.
pNX: The regional lymph nodes cannot be evaluated.
pN0: Cancer has not spread to the regional lymph nodes.
pN1: Cancer has spread to one inguinal lymph node, which is the cluster of lymph nodes in the groin.
pN2: Cancer has spread to more than one inguinal lymph node on one or both sides of the body.
pN3: The cancer has spread to one or more inguinal, or groin, lymph nodes, and it has grown from that lymph node into the surrounding tissue in the groin, and/or the cancer has spread to lymph nodes in the pelvis, on one or both sides of the body.
Distant metastasis. The “M” in the TNM system indicates whether the cancer has spread from the penis to other parts of the body.
MX: Distant metastasis cannot be evaluated.
M0: There is no distant metastasis.
M1: There is metastasis to parts of the body other than the penis and the regional lymph nodes.
Cancer stage grouping
Doctors assign the stage of the cancer by combining the T, N, and M classifications.
Stage 0: The cancer has not grown below the surface layer of skin, and it has not spread to lymph nodes or distant parts of the body (Tis or Ta; N0, M0).
Stage I: A low-grade cancer that has grown just below the surface layer of skin. It has not spread to lymph nodes or distant parts of the body (T1a, N0, M0).
Stage II: The cancer is invasive and is high grade and/or has grown into blood or lymph vessels and/or into the internal chambers of the penis and/or the urethra. It has not spread to lymph nodes or distant parts of the body (T1b, T2, or T3; N0, M0).
Stage IIIa: The tumor does not extend beyond the penis and urethra and has spread to one groin lymph node, but it has not spread to distant parts of the body (T1, T2, or T3; N1, M0).
Stage IIIb: The tumor does not extend beyond the penis and urethra, and has spread to more than one groin lymph node, but it has not spread to pelvic lymph nodes or distant parts of the body (T1, T2, or T3; N2, M0).
Stage IV: Any of the following:
- The cancer has grown into nearby tissues such as the pubic bone, the scrotum, or the prostate (T4, any N, any M).
- The cancer has spread to one or more lymph nodes in the groin, and it has grown from that lymph node into the surrounding tissue in the groin (any T, N3, M0).
- The cancer has spread to at least one lymph node in the pelvis (any T, N3, M0) and/or to distant lymph nodes outside the pelvis or to other parts of the body (any T, any N, M1).
Recurrent: Recurrent cancer is cancer that has come back after treatment. If there is a recurrence, the cancer may need to be staged again, called re-staging, using the system above.
Used with permission of the AJCC, Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition, published by Springer-Verlag New York, www.cancerstaging.org.
Information about the cancer’s stage will help the doctor recommend a treatment plan. The next section helps explain the treatment options for this type of cancer. Use the menu on the side of your screen to select Treatment Options, or you can select another section, to continue reading this guide.