How is Colon Cancer Staging Determined?

Colon Cancer Staging is an Important Part of Your Colon Cancer Treatment Plan

different stages of colon cancer
Medical illustration depicting the different stages of colon cancer. Getty/Stocktrek Images

Do you know how colon cancer staging is determined? The staging takes place after the initial diagnosis of colon cancer. To stage your colon cancer, your doctor will assess the extent of your disease. This information will be used to determine what treatment plan is best for you.

What is Colon Cancer Staging?

Your doctor will consider all of your test results together to determine the extent or stage of your disease.

The stage of cancer refers to how far it has spread beyond the location where it first developed in your body. Your doctor will use this information to develop the right treatment plan for you.

How Does Colon Cancer Staging Take Place?

To first get a diagnosis of colon cancer, your doctor will need to collect a tissue sample, called a biopsy, from your colon during a flexible sigmoidoscopy or colonoscopy test. If this biopsy comes back showing colon cancer, your doctor will schedule you for surgery. This will allow the doctor to determine the extent, or stage, of your disease.

During surgery, the surgeon may remove portions of your colon. This tissue can be tested to see how far the colon cancer has spread. In addition to removing the cancer and possibly parts of your colon, the doctor may remove lymph nodes. These are glands located throughout the body that are part of the immune system.

When colon cancer spreads beyond the colon, it will often go into the lymph nodes that are closest to the tumor.

By looking at your lymph nodes, the doctors can determine how far the cancer has spread.

What are Colon Cancer Staging Systems?

There are several different systems or ways of classifying colon cancer disease stage, but the most common is the American Joint Committee on Cancer (AJCC) system. You might also hear this referred to as the “TNM system.” T, N and M refer to three different aspects of colon cancer staging.

Along with the T, N and M, you will see numbers. Generally, the higher the number or letter, the more advanced the cancer is.

What Do the T, N, and M Labels of Colon Cancer Staging Mean?

The T indicates how far the colon tumor has grown into your intestine wall. It also indicates whether the tumor has penetrated through the wall of the intestine into nearby areas.

The N describes whether and how far the cancer has spread into nearby lymph nodes. Lymph nodes are glands located throughout the body that are part of the immune system. When colon cancer spreads beyond the colon, it will often go into the lymph nodes that are closest to the tumor.

The M indicates whether the cancer has spread to other organs or areas of the body. The M refers to “metastasis,” which is the technical term that is used to describe when a cancer has moved into other body areas or organs.

The numbers that appear after T, N, and M provide more detail and indicate the severity of each feature. The higher the number, the more advanced the disease.

For example, T1 means the tumor has just penetrated through the first layer of the colon, while a T3 means it has grown all the way into the outermost layers of the colon. As another example, N1 means the tumor has spread into one to three nearby lymph nodes, while an N2 means the tumor has spread to four or more lymph nodes.

Sometimes you may see the letter “x” by T, N, and M. This means the doctor did not have enough information to make a determination for that particular feature or aspect of your cancer.

What is Stage Grouping of Colon Cancer Staging?

Once your doctor determines your T, N, M staging, he or she will classify your disease by a stage group. These groups range from stage 0 through stage IV, with stages II and III in between. The higher the stage grouping, the more advanced the disease.

Based on your stage grouping, your doctor will develop a detailed treatment plan. This could include more surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy such as monoclonal antibodies, or some combination of these.

The more you learn about your colon cancer treatment options, the more confident you will be working with your doctor to make the best treatment decisions for you.

Treatment Options for Colon Cancer provides more detailed information about colon cancer staging and how it is used to determine the best treatment plan for each patient.


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