What Are the Stages of Anal Cancer?
The stages of anal cancer are used to describe how far the cancer has spread in your body. The higher the stage number, the more widespread the cancer is. These stages are important when choosing the best treatments for you.
One way to describe the stages of anal cancer is with the TNM system. This system uses three different codes to describe the size and location of the tumor, whether it has spread to the lymph nodes around the tumor, and whether it can be found in other parts of the body.
In the TNM system, “T” plus a letter or number (0 to 4) is used to describe the size and location of the tumor. The tumor stages for anal cancer are:
TX - The primary, or original, tumor cannot be evaluated because of incomplete information.
T0 - There is no evidence of a primary tumor.
Tis - Carcinoma in situ (very early cancer that is found only in the anus).
T1 - The tumor is 2 centimeters (about three-fourths of an inch) or smaller.
T2 - The tumor is between 2 centimeters and 5 centimeters (about 2 inches).
T3 - The tumor is larger than 5 centimeters.
T4 - The tumor is any size and has spread into nearby organs, such as the vagina, urethra (tube that carries urine out of the bladder), or bladder.
The "N" in the TNM system stands for node. Lymph nodes are tiny organs shaped like beans that can be found throughout the body. Lymph nodes help the body fight infections. Regional lymph nodes are near the anus, while distant lymph nodes are in other parts of the body. Lymph node stages are:
NX - The regional lymph nodes cannot be evaluated because of incomplete information.
N0 - The cancer has not spread into the regional lymph nodes.
N1 - The cancer has spread to lymph nodes near the rectum.
N2 - The cancer has spread to lymph nodes on one side of the groin (area where the thigh meets the hip) and/or pelvis.
N3 - The cancer has spread to lymph nodes near the rectum and in the pelvis or groin, or to both sides of the pelvis or groin.
The "M" in the TNM system is used for cancer that has spread, or metastasized, to other parts of the body. The stages for metastatic anal cancer are:
MX - Distant metastasis cannot be evaluated because of incomplete information.
M0 - The cancer has not metastasized, or spread, to other parts of the body.
M1 - The cancer has spread to other parts of the body.
Cancer Stages 0 to IV
After the T, N, and M categories of your cancer have been identified, your doctor will combine this information to assign a stage (I to IV) to your cancer. The higher the number, the more serious (advanced) the cancer is.
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Stage 0 (carcinoma in situ) - This very early cancer is found only in the top layer of the anal tissue (Tis, N0, M0).
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Stage I - The cancer has spread beyond the top layer of anal tissue but is less than 2 centimeters (about four-fifths of an inch) and is located only in the anus (T1, N0, M0).
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Stage II - The cancer is larger than 2 centimeters, but has not spread to lymph nodes or other parts of the body (T2 or T3, N0, M0).
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Stage IIIA - The cancer is any size and has spread to the lymph nodes around the rectum, or it has grown into nearby organs (such as the vagina or bladder), but has not spread to the lymph nodes (T1-T3, N1, M0; or T4, N0, M0).
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Stage IIIB - The cancer has spread to the lymph nodes in the middle of the abdomen or in the groin, or the cancer has spread to both nearby organs and the lymph nodes around the rectum (T4, N1, M0; or any T, N2 or N3, M0).
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Stage IV - The cancer is any size and has spread to distant lymph nodes in the abdomen or to organs in other parts of the body (any T, any N, M1).
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Recurrent - The cancer has come back (recurred) in the anus or another part of the body after it has been treated.
This content has been reviewed and approved by Myo Thant, MD.
This content was last modified on
March 24, 2008
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