When found early, colorectal cancer is very treatable by surgery, chemotherapy and/or radiation. Indeed the 5-year survival rate is 90 percent when colorectal cancer is discovered early.

Unfortunately, most colorectal cancer are not diagnosed at an early stage.

After a cancer has been found, the stage must be determined to decide on appropriate treatment. The stage tells how far the tumor has invaded the colon wall, and if it has spread to other parts of the body.

Stage 0 (Carcinoma in Situ)

In stage 0, the cancer is found in the innermost lining of the colon only. Stage 0 cancer is also called carcinoma in situ.

Stage I

In stage I, the cancer has spread beyond the innermost lining of the colon to the second and third layers and involves the inside wall of the colon, but it has not spread to the outer wall of the colon or outside the colon. Stage I colon cancer is sometimes called Dukes' A colon cancer.

Stage II

In stage II, cancer has spread outside the colon to nearby tissue, but it has not gone into the lymph nodes. (Lymph nodes are small, bean-shaped structures that are found throughout the body. They filter substances in a fluid called lymph and help fight infection and disease.) Stage II colon cancer is sometimes called Dukes' B colon cancer.

Stage III

In stage III, cancer has spread to nearby lymph nodes, but it has not spread to other parts of the body. Stage III colon cancer is sometimes called Dukes' C colon cancer.

Stage IV

In stage IV, cancer has spread to other parts of the body, such as the liver or lungs. Stage IV colon cancer is sometimes called Dukes' D colon cancer.

After the tumor and lymph nodes are removed by a surgeon, they are examined by a pathologist, who determines how much of the colon wall and lymph nodes have been invaded by tumor. Patients with invasive cancer (stages II, III, and IV) require a staging workup, including full colonoscopy, carcinoembryonic antigen (CEA) level (a marker for colon cancer found in the blood), chest x-ray, and CT scan of the abdomen and pelvis, to determine if the cancer has spread.

What are the Treatments for Colon Cancer?

Surgery

Surgery (removing the cancer in an operation) is the most common treatment for all stages of colon cancer. A doctor may remove the cancer using one of the following types of surgery:

Local excision: If the cancer is found at a very early stage, the doctor may remove it without cutting through the abdominal wall. Instead, the doctor may put a tube through the rectum into the colon and cut the cancer out. This is called a local excision. If the cancer is found in a polyp (a small bulging piece of tissue), the operation is called a polypectomy.

Resection: If the cancer is larger, the doctor will perform a colectomy (removing the cancer and a small amount of healthy tissue around it). The doctor may then perform an anastomosis (sewing the healthy parts of the colon together). The doctor will also usually remove lymph nodes near the colon and examine them under a microscope to see whether they contain cancer.

Resection and colostomy: If the doctor is not able to sew the 2 ends of the colon back together, a stoma (an opening) is made on the outside of the body for waste to pass through. This procedure is called a colostomy. Sometimes the colostomy is needed only until the lower colon has healed, and then it can be reversed. If the doctor needs to remove the entire lower colon, however, the colostomy may be permanent.

Even if the doctor removes all the cancer that can be seen at the time of the operation, some patients may be offered chemotherapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to increase the chances of a cure, is called adjuvant therapy.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be taken by mouth, or it may be put into the body by inserting a needle into a vein or muscle. Either type of chemotherapy is called systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body.

Despite the fact that a majority of patients have the entire tumor removed by surgery, as many as 40 percent will develop a recurrence. Chemotherapy is given to reduce this chance of recurrence.

Generally, patients with stage II disease who present with a bowel perforation or obstruction, or have poorly differentiated tumors (determined by a pathologist), are considered at higher risk for recurrence, and are treated with 6 to 8 months of Fluorouracil (5-FU) and Leucovorin (LV) (both chemotherapy agents). Other patients with stage II disease are followed closely, but generally receive no chemotherapy.

Patients who present with stage III colon cancer are typically treated with a regimen of Fluorouracil and Leucovorin for 12 months.

Forty to fifty percent of patients have metastatic (disease that has spread to other organs) at the time of diagnosis, or have a recurrence of the disease after therapy. Unfortunately, the prognosis for these patients is poor.

The standard therapy for patients with advanced disease is Fluorouracil, Leucovorin, and irinotecan (CPT-11). This regimen was found to be more effective than Fluorouracil and Leucovorin alone in these patients.

Two new medications, capecitabine (Xeloda) and oxaliplatin, are also being used in the treatment of advanced colon cancer. Capecitabine is currently approved by the FDA for the treatment of advanced colon cancer that has failed treatment, but is still being investigated in untreated patients. Oxaliplatin is widely used in Europe, but has not yet been approved by the FDA for use in the United States. Currently, patients can only receive this medication in a clinical trial.

Radiotherapy

Radiation therapy is the use of x-rays or other types of radiation to kill cancer cells and shrink tumors.

Colon cancer is not typically treated with radiation therapy. If the cancer has invaded another organ, or adhered to the abdominal wall, radiation therapy may be one option.

All information provided in this site is offered for educational purposes only, and it is not intended nor implied to be a substitute for professional medical advice. Always consult your own physician or healthcare provider with any questions you may have regarding a medical condition.