Staging & Information

Colon Cancer Staging & Information

T Categories for Colorectal Cancer

Tx: No description of the tumor’s extent is possible because of incomplete information.

Tis: The cancer is in the earliest stage. It has not grown beyond the mucosa (inner layer) of the colon or rectum. This stage is also known as carcinoma in situ or intramucosal carcinoma.

T1: The cancer has grown through the mucosa and extends into the submucosa.

T2: The cancer has grown through the the submucosa, and extends into the muscularis propria.

T3: The cancer has grown completely through the muscularis propria into the subserosa but not to any neighboring organs or tissues.

T4: The cancer has spread completely through the wall of the colon or rectum into nearby tissues or organs.

N Categories for Colorectal Cancer

N categories indicate whether or not the cancer has spread to nearby lymph nodes and, if so, how many lymph nodes are involved.

Nx: No description of lymph node involvement is possible because of incomplete information.

N0: No lymph node involvement is found.

N1: Cancer cells found in 1 to 3 nearby lymph nodes.

N2: Cancer cells found in 4 or more nearby lymph nodes.

M Categories for Colorectal Cancer

M categories indicate whether or not the cancer has spread to distant organs, such as the liver, lungs, or distant lymph nodes.

Mx: No description of distant spread is possible because of incomplete information.

M0: No distant spread is seen.

M1: Distant spread is present.

Stage Grouping

Once a patient’s T, N, and M categories have been determined, usually after surgery, this information is combined in a process called stage grouping to determine the stage, expressed in Roman numerals from stage I (the least advanced stage) to stage IV (the most advanced stage). The following guide illustrates how TNM categories are grouped together into stages:

Stage 0:
Tis, N0, M0: The cancer is in the earliest stage. It has not grown beyond the inner layer (mucosa) of the colon or rectum. This stage is also known as carcinoma in situ or intramucosal carcinoma.

Stage I:
T1, N0, M0, or T2, N0, M0: The cancer has grown through the mucosa into the submucosa or it may also have grown into the muscularis propria, but it has not spread into nearby lymph nodes or distant sites.

Stage IIA:
T3, N0, M0: The cancer has grown through the wall of the colon or rectum into the outermost layers. It has not yet spread to the nearby lymph nodes or distant sites.

Stage IIB:
T4, N0, M0: The cancer has grown through the wall of the colon or rectum into other nearby tissues or organs. It has not yet spread to the nearby lymph nodes or distant sites.

Stage IIIA:
T1-2, N1, M0: The cancer has grown through the mucosa into the submucosa or it may also have grown into the muscularis propria, and it has spread to 1-3 nearby lymph nodes but not distant sites.

Stage IIIB:
T3-4, N1, M0: The cancer has grown through the wall of the colon or rectum or into other nearby tissues or organs and has spread to 1-3 nearby lymph nodes but not distant sites.

Stage IIIC:
Any T, N2, M0: The cancer can be any T but has spread to 4 or more nearby lymph nodes but not distant sites.

Stage IV:
Any T, Any N, M1: The cancer can be any T, any N, but has spread to distant sites such as the liver, lung, peritoneum (the membrane lining the abdominal cavity), or ovary.