Educational Articles

Treatment of Colon Cancer

The colon is a part of the digestive tract that connects the stomach and small intestine to the anus. Colon cancer is a cancerous growth that occurs in the lining of this colon. It is an extremely common problem worldwide, with over 1 million new cases of colon cancer diagnosed annually. It is thought that both environmental factors such as diet and smoking, as well as genetic factors play important role in the development of colon cancer.

The diagnosis of colon cancer often involves colonoscopy, an examination of the colon using an instrument called colonoscope that enables an evaluation of the inner lining of the colon as well as to take a biopsy or sampling of cancer tissue. Once the diagnosis of colon cancer is made, the extent of the disease is often determined using a radiologic examination called CT scan. It allows an initial assessment of the extent of spread of cancer. Often routine blood tests including complete blood count (CBC), liver function tests, and a tumor marker called CEA are obtained during the initial evaluation.

There are 4 stages of colon cancer. Colon cancer is defined as Stage 1, if the cancer tissue is confined to the lining of the colon or polyp. In Stage 2 colon cancer, the cancer tissue has invaded the layers of colonic wall, but has not yet spread beyond the wall. In Stage 3 colon cancer, the cancer tissue has penetrated the entire thickness of the colonic wall and spread to nearby lymph nodes. In Stage 4 colon cancer, the cancer has spread to other organs such as liver. The staging of colon cancer is important since the prognosis of affected individual is highly dependent on the staging of cancer.  

For cancer that has not spread, the surgery is the treatment of choice. In fact, surgery may be the only treatment necessary for patients with Stage 1 or 2 colon cancer. However, some with Stage 2 cancer may elect to receive chemotherapy. Following surgery to remove the colon cancer, Stage 3 cancer requires chemotherapy, usually for about 6 months. The most commonly used chemotherapy is called FOLFOX regimen consisting of 5-FU, leucovorin, and oxaliplatin. Some may also elect to receive additional treatment with a new class of cancer therapy such as Erbitux or Avastin. Treatment for Stage 4 colon cancer has to be individualized as a complete cure is unlikely, although many often also receive surgery and chemotherapy.