The National Cancer Institute estimates that there are 102,900 new cases of colon cancer in 2010. When the cancer is confined to the large intestines, surgery can cure about 50 percent of patients with colon cancer. More advanced stages of colon cancer often require surgery along with other treatments and unfortunately have a significantly lower level of success.
Staging
The doctor will determine the stage of cancer before beginning its treatment because the degree of spread dictates which treatments to try. Stages zero and one are early stages, before the cancer has penetrated beyond the surface layer of the colon. In stages three and four the cancer is advanced and has spread beyond the colon. In stage three, only nearby lymph nodes are affected. In stage four, the cancer has spread, or metastasized, to other organs.
Surgery
Surgery to remove the cancer lesion and nearby tissue is a standard treatment for all stages of colon cancer. The surgeon removes the affected portion of the colon and if possible, re-joins the two cut ends. In other cases the patient might need a temporary or permanent colostomy, a procedure that re-routes the colon into a special bag to receive digestive waste. In advanced cases where the cancer has spread beyond the colon, the surgeon will remove nearby lymph nodes as well. In very advanced cases, the of colon cancer, where the cancer has spread to other organs, colon surgery does not treat the cancer, but merely provides relief from some of the patient's symptoms.
In some cases of stage four colon cancer in which the cancer has spread only to the liver, a doctor might recommend colon surgery along with removal of the affected spots of the liver.
Chemotherapy and Radiation
Chemotherapy and radiation therapy use drugs and energy sources, respectively, to try to selectively kill fast-growing cancer cells. A doctor might recommend one or the other, or sometimes both, to shrink tumors before colon surgery, to prevent the recurrence after surgery, or to target areas of cancer outside of the colon.
Targeted Drugs
The Mayo Clinic lists a few drugs that specifically target colon cancer cells that can be useful for some people with advanced colon cancer. Drugs include panitumumab, cetuximab and bevacizumab. Because targeted drugs are expensive, can cause serious side effects, and have "limited benefit" according to the Mayo Clinic, doctors usually prescribe them only for people with advanced stages of colon cancer.
Prognosis
The Merck Manual cites a 10 year survival rate of 30 to 50 percent when colon cancer has spread to the lymph nodes and less than 20 percent when it has spread to other organs. The National Cancer Institute says that surgical removal of the lesions can cure colon cancer in 25 to 40 percent of patients whose cancer has metastasized to discrete, operable spots in the lungs or liver.
