Types of Treatment for Colon and Rectal Cancers

The 4 main types of treatment for colon and rectal cancer are surgery, radiation therapy, chemotherapy, and immunotherapy. Depending on the stage of the cancer, 2 or even 3 of these types of treatment may be combined at the same time or after one another.

After your cancer has been found and staged, your doctor will recommend one or more treatment options. It is important to take time and think about all of the choices. You may want to ask for a second opinion. This can provide more information and help you feel more confident about the treatment plan you choose.

Surgery

Colon surgery: Surgery is the main treatment for colon cancer. The usual operation is called a segmental resection or partial colectomy. To prepare for this surgery you will be given laxatives and enemas. Just before the surgery you will be given general anesthesia, which puts you into a deep sleep. During this surgery, the cancer and a length of normal tissue on either side of the cancer as well as the nearby lymph nodes are removed. The remaining sections of the colon are then attached back together. When you wake up you will have some pain and will need to be given pain medicines, usually morphine for the first day or two. This operation rarely causes any major permanent problems with digestive functions. Sometimes, a temporary colostomy may be needed. In a colostomy, the colon is attached to the abdominal wall and fecal material drains through an opening in the wall into a bag. Even more rarely, a permanent colostomy may be needed. Patients can usually leave the hospital about 5 to 7 days after surgery and resume usual activities in 6 weeks. Of course, hospitalization and recovery times depend on each patient’s specific medical condition.

It is sometimes possible to remove some very early colon cancers by surgery through a colonoscope. When this is done, the surgeon does not have to cut into the abdomen.

Some very advanced colon cancers can block the flow of feces. When it is not possible to remove the cancer, the flow of feces can be diverted to a colostomy. This operation is called a diverting colostomy. If there is blockage, surgery is more likely to lead to complications because the bowel cannot be cleansed with enemas, which help prevent infection. Also, a complete colonoscopy cannot be done.

It is sometimes possible to remove segments of the colon and nearby lymph nodes through a laparoscope. This instrument is a long, lighted viewing tube through which the doctor can operate with special surgical instruments. The viewing tube and instruments are placed into the abdomen through several small surgical incisions. The NCCN guidelines recommend laparoscopic colectomy as an option because clinical trials have shown that laparoscopic colectomy is as good a procedure as abdominal colectomy

Rectal surgery: Several methods are used for removing or destroying rectal cancers. Local resection is an option for some people with stage I rectal cancer. It involves cutting through all layers of the rectum to remove invasive cancers as well as some surrounding normal rectal tissue. This procedure can be done through the anus without cutting through the abdomen and it leaves the rectum intact. This procedure is called “transanal resection.” Because complete removal of the cancer is so important, local resection is not an option for people whose cancers cannot be completely removed by that procedure. Doctors consider the cancer’s size, its exact location within the rectum, and how far around the circumference of the rectum it extends in order to select which patients should have a local resection.

Many stage I and most stage II and stage III rectal cancers are removed by either low anterior (LA) resection or abdominoperineal (AP) resection. LA resection is used for cancers near the upper part of the rectum, close to where it connects with the sigmoid colon. After LA resection, the colon is attached to the lower rectum and waste is eliminated in the usual way.

AP resection is used for cancer in the lower part of the rectum, close to its outer connection to the anus. Because the cancer is close to the anus, the anus is also removed. After AP resection, a permanent colostomy is needed. Some patients with stage IV rectal cancers will need a diverting colostomy. In this operation the surgeon does not remove a rectal cancer that is blocking fecal flow, but instead bypasses the blockage and diverts fecal flow to a colostomy. Some patients may now have a stent (a plastic or metal tube) placed to keep the colon or rectum from becoming blocked if the tumor cannot be removed. Heating the rectal tumor with a laser beam aimed through the anus, called photocoagulation, is another option for relieving or preventing rectal blockage in patients with stage IV cancer.

Surgical treatment of colorectal cancer metastases: For patients whose colorectal cancer has spread to a few areas in the liver, lungs, or elsewhere in the abdomen, removing these metastases can cure the cancer in some instances. Other times, destroying metastases without surgery, although not curative, can help the patient live longer. Liver metastases may also be destroyed by freezing the tumor (cryosurgery) or by heating them with microwaves (radio frequency ablation). The freezing probe or microwave probe is placed through the skin and guided to the tumor by CT scans or ultrasound images.

Radiation Therapy

Radiation has a major role in the treatment of rectal cancers. Radiation therapy uses high-energy x-rays or particles to kill cancer cells. In treating rectal cancer, radiation treatment is usually given by external beam radiation. External beam radiation is usually given with a linear accelerator, 5 days a week for several weeks. This must be planned, using diagnostic x-ray machines, such as a simulator or a CT scanner. Radiation can be given either before surgery — to cause the tumor to shrink to allow easier removal or to decrease the risk of complications — or after surgery if there is a risk of the cancer coming back in the tumor area. Chemotherapy with the drug fluorouracil (5-FU) is given by continuous infusion through an intravenous (IV) line (placed in a vein) at the same time as radiation to make the radiation more effective. Studies have shown that for cases of rectal cancer, radiation along with surgery will often decrease the risk of the cancer coming back (recurrence).

Chemotherapy

Chemotherapy is the use of cancer-fighting drugs injected into a vein or taken by mouth. Chemotherapy is a systemic treatment. The drugs enter the bloodstream and reach all areas of the body, making this treatment useful for cancers that have spread beyond the organ they started in.

Fluorouracil (5-FU) is the chemotherapy drug most often used to treat colorectal cancer. It is usually given together with other drugs, such as leucovorin, that increase its effectiveness. As stated above, 5-FU is also given by continuous infusion along with radiation therapy to increase the effectiveness of the radiation.

In the past, 5-FU was usually given slowly into a vein over about 5 minutes. If these injections were given for 5 days, which was a typical treatment, no other chemotherapy would be given for about 3 weeks while the patient recovers from the drug’s side effects. Some doctors would use a schedule of once weekly injections. This cycle was repeated for 6 to 8 months.

Recently it has been found that a different way of giving these drugs may be better. With this treatment, called the de Gramont regimen, the 5-FU is given continuously over 2 days as well as by rapid injection on each day. The leucovorin is given on each day over 2 hours. The de Gramont regimen is given every other week.

In some cases, particularly along with radiation therapy, 5-FU is given as a continuous infusion into a vein. The patient wears a small battery-operated pump that continuously releases 5-FU into an IV line. For patients with spread of colon or rectal cancer to their liver, 5-FU or a related drug, floxuridine (FUDR), may be given directly into the artery that supplies blood to the liver. This approach to treatment of liver metastases is called hepatic artery infusion.

Irinotecan is another chemotherapy drug that is used with 5-FU. This treatment is called FOLFIRI. It adds irinotecan to the de Gramont 5-FU/leucovorin regimen. Recent studies have shown a chance of excessive side effects when 5-FU, leucovorin, and irinotecan are combined. If this combination of drugs is used, the starting doses may be reduced and your doctor will carefully watch you so that your doses can be adjusted if necessary. If excessive side effects occur, dosages may be adjusted.

Oxaliplatin is another drug that is effective when combined with 5-FU and leucovorin and may be used instead of irinotecan. Like irinotecan, it is often used with the de Gramont 5-FU/leucovorin regimen. This treatment is called FOLFOX.

Capecitabine , a chemotherapy drug given by mouth, is changed to 5-FU once it gets inside the body to the tumor site. This drug can be used instead of intravenous 5-FU and acts as if the 5-FU was being given continuously.

Immunotherapy

Immunotherapies use natural substances produced by the immune system. These substances may kill cancer cells, slow their growth, or activate the patient’s immune system to fight cancer more effectively.

Antibodies are produced by the immune system to help fight infections. Similar antibodies called monoclonal antibodies can be made in the laboratory. Instead of attacking germs as usual antibodies do, some monoclonal antibodies can be designed to attack cancer cells. Two new monoclonal antibodies have been approved by the US Food and Drug Administration (FDA) to attack colon cancer cells.

The first new agent, bevacizumab, works by preventing the growth of new blood vessels that supply tumor cells with the blood, oxygen and other nutrients they need to grow. Bevacizumab is used with chemotherapy as first line treatment for patients with advanced or metastatic colon or rectal cancer.

The second new agent, cetuximab, works by binding to a special site on the cell surface which stops the cell’s growth and promotes cell death. It is used either alone or in combination with a chemotherapy agent as a second line treatment for patients with advanced cancer or metastatic colon or rectal cancer whose disease is no longer responding to the chemotherapy agent, irinotecan, or for patients who cannot take irinotecan.

Adjuvant Treatment and Neoadjuvant Treatment

The terms adjuvant treatment and neoadjuvant therapy refer to radiation therapy and/ or chemotherapy given before (neoadjuvant) or after (adjuvant) surgery. Adjuvant treatment is given after surgery when there is a chance that a small number of cancer cells have already spread to distant sites. Neoadjuvant therapy is given before surgery for large rectal tumors, particularly if the cancer appears to have spread to lymph nodes.

Adjuvant treatment: After surgery, the tissue that has been removed is examined under a microscope to determine the cancer’s stage (how far it has spread). If the cancer is large or has spread to lymph nodes, even though no remaining cancer can be seen, doctors believe it is possible that a few scattered cancer cells may remain in the patient’s body. In this situation more treatment in the form of chemotherapy or radiation therapy may be given.

Neoadjuvant treatment: If the tumor appears large or has spread to lymph nodes, radiation therapy along with chemotherapy may be recommended before surgery. The purpose of neoadjuvant treatment is to shrink tumors so that they can be more completely removed by surgery and prevent the cancer from coming back in the pelvis.

Talking with an enterostomal therapist: NCCN guidelines recommend that people with rectal cancer be referred to an enterostomal therapist (a health care professional, often a nurse, trained to help people with their colostomies) as part of their initial work-up. The enterostomal therapist can address concerns about how a colostomy might affect their daily activities. A colostomy is an opening in the abdomen where a section of the colon is attached to allow for passage of body waste. A bag is attached to the skin with adhesives to collect waste. Discussing these issues shortly after diagnosis can help patients make informed decisions about treatment options, some of which may involve a colostomy.

A discussion with an enterostomal therapist is also recommended for the few people with colon cancer who need a temporary or permanent colostomy. If a patient’s surgical treatment requires a colostomy, the enterostomal therapist will provide information and training on care of the colostomy. The ACS and many cancer centers can refer patients with colostomies to support groups and other programs that provide additional information and support.

Treatment of Pain and Other Symptoms

Most of this document discusses ways to remove or destroy colorectal cancer cells or to slow their growth. But it is important to realize that maintaining the lifestyle you have always enjoyed is an important goal. Don’t hesitate to discuss your symptoms or any other concerns with your cancer care team. There are effective and safe ways to treat pain, most other symptoms of colorectal cancer, and most of the side effects caused by colorectal cancer treatment. (Refer to the ACS/NCCN treatment guidelines for patients on the following topics: cancer pain, nausea and vomiting, cancer-related fatigue, and fever and neutropenia.)

Alternative or Complementary Therapies

If you are considering any alternative or complementary therapies, it is best to discuss this openly with your cancer care team and request information from the ACS or the National Cancer Institute (NCI). Any treatment that has not be studied in clinical trials and proved to be safe and effective might interfere with standard medical treatments or cause serious side effects.

STAGES OF COLON AND RECTAL CANCER

SIDE EFFECTS OF COLON AND RECTAL CANCER TREATMENTS

For more information on these treatment guidelines, or on cancer in general, call the NCCN at 1-888-909-NCCN or the American Cancer Society at 1-800-ACS-2345. Or you can visit these organizations’ web sites at www.cancer.org (ACS) and www.nccn.org (NCCN).

© 2005 by the National Comprehensive Cancer Network (NCCN) and the American Cancer Society (ACS). All rights reserved. The information herein may not be reproduced in any form for commercial purposes or downloaded and stored in any information-retrieval system without the express written permission of the NCCN and the ACS. Single copies of each page may be printed out for personal, noncommercial use only.