What Are the Stages of Colorectal Cancer?
Stages of cancer are a way to describe the tumor and where it has spread. Knowing the stage of your cancer helps your doctors decide what type of treatment is most likely to help you.
TNM System
One way to describe the stages of colorectal cancer is to use the TNM system. This system uses three different codes to describe how far the tumor has gone through the layers of the colon or rectum wall, 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 depth of the tumor in the bowel lining. The tumor stages are:
TX -The regional lymph nodes cannot be evaluated because of incomplete information.
T0 -There is no evidence of cancer in the colon or rectum.
Tis - Cancer cells are found only in the lining inside the colon or rectum.
T1 - The tumor has grown into the layer of tissue underneath the lining of the colon or rectum.
T2 - The tumor has invaded the thick layer of muscle that squeezes to move the contents of the intestines along.
T3 - The tumor has grown into the thin layer of connective tissue under the outer layer of some parts of the large intestine or into tissues surrounding the colon or rectum.
T4 - The tumor has moved into other organs or has caused a hole in the wall of the colon or rectum.
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 infection. Regional lymph nodes are near the colon and rectum. Lymph nodes in other parts of the body are known as distant lymph nodes. 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 one to three regional lymph nodes.
N2 - The cancer has spread to four or more regional lymph nodes.
The "M" in the TNM system is used for cancer that has spread to other parts of the body, often the liver or lungs. The stages for metastatic colorectal cancer (cancer that has spread to other organs) 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 beyond the colon or rectum.
Cancer Stages 0 to IV
The National Cancer Institute defines the following stages for colorectal cancer based on information from the TNM system:
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Stage 0 (cancer in situ or carcinoma in situ) - The cancer is found only in the innermost lining of the colon or rectum (Tis, N0, M0).
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Stage I
- The cancer has spread beyond the innermost lining of the colon or rectum to the second and third layers and the inside wall of the colon or rectum. The cancer has not spread to the outer wall of the colon or outside of the colon (T1, N0, M0).
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Stage II
- The cancer has spread outside the colon or rectum to nearby tissue. However, the cancer has not spread to the lymph nodes (T3 or T4, N0, M0).
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Stage III - The cancer has spread to nearby lymph nodes, but has not spread to other organs in the body (any T, N1 or N2, M0).
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Stage IV - The cancer has spread to other parts of the body, such as the liver or lungs (any T, any N, M1).
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Recurrent cancer - The cancer has been treated and was not detected for a period of time. However, it has returned in the colon, rectum, or another part of the body.
This content was last modified on
July 14, 2008
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