There are several methods to stage colon cancer. TNM classifications and Duke’s staging methods are the most common.

The TNM classification is more precise as “T” represents tumors. Cancer is classified, depending on the depth of the tumor’s invasion into the bowel wall. “N” stands for lymph nodes and is ranked according to the number of lymph nodes affected and if it has spread. “M” relates to the tumor and if it has spread to other distant organs.

Duke’s classification divides the colon and rectal cancers into three stages, namely A, B, and C colon cancers. Type A cancers are confined to the muscular lining of the wall of the intestine. When cancer has spread beyond the muscular layer of the bowel wall, it is type B cancer. Type C cancer, on the other hand, would be the type that has spread to the lymph nodes and beyond.

Most often, the cancer tumor at stage 1 is classified as Duke’s A lesion, as it is confined to the bowel wall. Stage 2 cancer tumors would be classified as Duke’s B lesion, as it would have grown beyond the muscular layer of the bowel wall. In stage, it is considered as a Duke’s C lesion where the colon cancer spreads to the lymph nodes. In the fourth stage, cancer spreads to distant organs.

The staging of cancer is important to predict the probability of recurring cancer after surgical removal. To also determine whether chemotherapy helps prevent or reduce the chances of cancer recurrence, staging is important. Chemotherapy is usually used after surgery in stages 2, 3, and 4, as it has shown an increase in survival rates. In most cases of stage 1 cancer, there is usually no need for chemotherapy as it can be cured with surgery alone.

When is chemotherapy used for colon cancer?
This therapy is used at various times during the treatment of colon cancer.

Adjuvant chemo
This treatment is given after surgery to kill any cancer cells that are still alive. This is because they are small and sometimes the cancer cells might have escaped the main tumor and settled in other parts of the body. This kind of treatment helps to lower the chances of cancer recurrence.

Neoadjuvant chemo
This therapy is given along with radiation before surgery. This helps to shrink cancer, making it easy to remove during surgery. It is done quite often for patients with rectal cancer.

Chemo for advanced cancers
Usually, chemotherapy is given in cases where the cancer is advanced and has spread to other organs, like the liver. It is used mainly to help shrink tumors and ease problems that arise. This treatment is not likely to cure cancer, but it helps one live longer.

If found at early stages, colon cancer is curable, especially if it is diagnosed in a precancerous state. Surgery and chemotherapy have improved rates for colon cancer but it is ideal to diagnose colon lesions before they become malignant.