Colon Cancer Staging

Colon cancer staging is very important. It is a method used by oncologists, or doctors specializing in cancer, to grade the progress of the disease. It takes into consideration the extent of how much the cancer has spread in the body. It also looks on whether the cancer cells have affected lymph nodes or not and how much damage it has done to the organ that it is affecting.

Staging can be done in three ways.

Modified Duke’s system

The first of the three colon cancer staging method is the (Modified) Duke’s system. In this system, the doctors will classify the progress of cancer according to how much penetration the tumor has done to the organ’s mucosa. In this system, the lowest classification, also the one that gives the highest percentage of recovery is A. the highest classification, also the one that gives the poorest prognosis, is B.

Modified Duke A

In this stage, the tumor has only penetrated the mucosa of the colon and nothing more.

Modified Duke B1 This stage shows that the tumor has penetrated the colon’s mucosal wall. However, it has not gone thru the mucosal wall itself.

Modified Duke B2 As expected, in this stage the tumor has penetrated the colon mucosal wall and gone through it.

Modified Duke C1 In this stage, the tumor has penetrated the colon mucosal wall but has not gone through it. This time, the cancer cells have begun to affect lymph nodes.

Modified Duke C2

This stage will show that the tumor has penetrated the colon mucosal wall and has even gone through it. At the same time there is also evidence that the lymph nodes are affected by the cancer cells.

Modified Duke D

This is the last stage in the Modified Duke colon cancer staging. In this stage, the tumor has affected even the organs that are far from the original site of the cancer cells. In this stage, there is now metastasis.

At present, the Modified Duke System is not as commonly used as it was years ago.

Tumor, Node, Metastasis or TNM System

The American joint Committee has come up with another way of staging colon cancer. The system they introduced is the Tumor, Node, Metastasis or TNM System.

For the Tumor staging, there are four stages that are involved.

* T1 is the stage where the tumor has invaded the sub-mucosa

* T2 is the stage wherein the tumor has invaded further to include the muscular layer of the organ affected

* T3 is the stage wherein the tumor has gone through the muscular layer and can even include the perirectal tissues

* T4 is the stage where the tumor has affects and perforates other organs.

The Node staging centers on the lymph node involvement of the cancer. In this system, there are three stages involved.

* N0 simply means that there is no lymph node involved in the cancer

* N1 implies that there is now one to three lymph nodes affected by the cancer

* N2 is the classification given to a cancer that has involved four or more lymph nodes

The last in the TNM colon cancer staging system is the metastasis portion. This system pertains to whether or not the cancer has spread to other organs. With this, there is only one stage and that is M0. It means that there is no distant metastasis.

Stage grouping

Stage grouping is a cancer staging system that incorporates the TNM classification under one stage. There are five stages involved in this system. The lowest stage is stage 0 wherein there is a very good prognosis. The highest stage is stage IV where the prognosis is bad.

Stage 0 is the stage where the cancer cells are confined in their originating tissue and in a polyp. This is why this stage is also called as “cancer in situ”.

Stage I cancer shows that the abnormal cells are still in the innermost layer of the colon but has gone to spread to include the sub-mucosa.

Stage II diagnosis is made when the cancer cells have penetrated even the mucosal walls of the colon. In fact, this stage can also show that the cancer has affected other organs especially those that are near the colon.

Stage III is the classification used for cancer that has involved a lymph node or two. In this stage, the cancer has penetrated all the layers of colon as well as affected to the nearby organs.

Stage IV is when the cancer has affected more than 4 lymph nodes as well as metastasized to distant body organs.

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