Treatment of Colon Cancer

The choice of treatment depends mainly on the location of the tumor in the colon or rectum and the stage of the disease. Treatment for colorectal cancer may involve surgery, chemotherapy, biological therapy or radiation therapy. Some people have a combination of treatments. Colon cancer sometimes is treated differently from rectal cancer.

Cancer treatment is either local therapy or systemic therapy:

• Local therapy: Surgery and radiation therapy are local therapies. They remove or destroy cancer in or near the colon or rectum. When colorectal cancer has spread to other parts of the body, local therapy may be used to control the disease in those specific areas.
• Systemic therapy: Chemotherapy and biological therapy are systemic therapies. The drugs enter the bloodstream and destroy or control cancer throughout the body.

Surgery

Surgery is the most common treatment for colorectal cancer.

• Colonoscopy: A small malignant polyp may be removed from the colon or upper rectum with a colonoscope. Some small tumors in the lower rectum can be removed through the anus without a colonoscope.
• Laparoscopy: Early colon cancer may be removed with the aid of a thin, lighted tube (laparoscope). Three or four tiny cuts are made into the abdomen. The surgeon sees inside the abdomen with the laparoscope. The tumor and part of the healthy colon are removed. Nearby lymph nodes also may be removed. The surgeon checks the rest of your intestine and the liver to see if the cancer has spread.
• Open surgery: The surgeon makes a large cut into the abdomen to remove the tumor and part of the healthy colon or rectum. Some nearby lymph nodes are also removed. The surgeon checks the rest of the intestine and the liver to see if the cancer has spread. Open surgery may be needed if tumor is difficult to remove using laprascopy.
• Colostomy: A colostomy is an incision into the colon to create an artificial opening or "stoma" to the exterior of the abdomen. This opening serves as a substitute anus through which the intestines can eliminate waste products until the colon can heal or other corrective surgery can be done. The bowel movements fall into a collection pouch which can be emptied periodically at home.

Chemotherapy

Chemotherapy uses anticancer drugs to kill cancer cells. The drugs enter the bloodstream and can affect cancer cells all over the body.

Anticancer drugs are usually given through a vein, but some may be given by mouth. The side effects of chemotherapy depend mainly on the specific drugs and the dose. The drugs can harm normal cells that divide rapidly:

• Blood cells: These cells fight infection, help blood to clot, and carry oxygen to all parts of your body. When drugs affect blood cells, the patient is more likely to get infections, bruise or bleed easily, and feel very weak and tired.
• Cells in hair roots: Chemotherapy can cause hair loss. Hair will grow back, but it may be somewhat different in color and texture.
• Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores.

Chemotherapy for colorectal cancer can cause the skin on the palms of the hands and bottoms of the feet to become red and painful. The skin may peel off.

Biological Therapy

Some people with colorectal cancer that has spread receive a monoclonal antibody, a type of biological therapy. The monoclonal antibodies bind to colorectal cancer cells or bind to circulating chemical signals that promote tumor growth. They interfere with cancer cell growth and the spread of cancer. These monoclonal antibodies are frequently given together with chemotherapy, but can be continued by itself once cancer control has been optimized.

Some people get medicine to prevent a possible allergic reaction. The side effects depend mainly on the monoclonal antibody used. Side effects may include rash, fever, abdominal pain, vomiting, diarrhea, blood pressure changes, bleeding, or breathing problems. Side effects usually become milder after the first treatment.

Radiation Therapy

Radiation therapy uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area. Different types of radiation therapies are used to treat cancer. Sometimes people receive two types:

• External-beam radiation: The radiation comes from a machine. The most common type of machine used for radiation therapy is called a linear accelerator. With modern techniques using computer technology, external-beam radiation can be delivered precisely with minimal effect on surrounding tissues.
• Internal radiation (implant radiation or brachytherapy): The radiation comes from radioactive material placed in thin tubes put directly into or near the tumor. The patient stays in the hospital, and the implants generally remain in place for several days. Usually they are removed before the patient goes home. This type of treatment is not commonly done for colorectal cancer.
• Intraoperative radiation therapy (IORT): In some cases, radiation is given during surgery.

Nutrition and Physical Activity

It is important to eat well and stay active. The right amount of calories is required to maintain a good weight during and after cancer treatment. Eating well may help feel better and have more energy. Some people may have nausea, vomiting, diarrhea, or mouth sores. The health care provider can suggest ways to deal with these problems. Many people find they feel better when they stay active. Walking, yoga, swimming, and other activities can keep you strong and increase your energy.

Rehabilitation

Rehabilitation is an important part of cancer care. The health care team makes every effort to help return to normal activities as soon as possible.

Follow-up Care

Follow-up care after treatment for colorectal cancer is important. Even when the cancer seems to have been completely removed or destroyed, the disease sometimes returns because undetected cancer cells remained somewhere in the body after treatment. Checkups help ensure that any changes in health are noted and treated if needed.

Checkups may include a physical exam, lab tests, colonoscopy, x-rays, CT scans or other tests.

Sources
National Cancer Institute http://www.cancer.gov
Centers for Disease Control and Prevention http://www.cdc.gov