Approximately 85% of patients with CRC can have a curative operation to remove the involved colon and mesentery. Patients need a preoperative colonoscopy and CT of the abdomen to rule out liver metastases. Any colonic or rectal polyps are removed. Resections that save the sphincter in patients with rectal cancer assist in reducing the number of abdominoperineal excisions necessary. 5-Fluorouracil (5-FU) is a cytostatic drug that inhibits DNA synthesis in cancer cells.

The postoperative use of 5-FU along with levamisole, an immunomodulator drug, improves postoperative cure rates. Levamisole is believed to antagonize the effect of 5-FU on RNA synthesis, potentially reducing the toxicity associated with 5-FU administration. Similarly, improved cure rates are noted when leucovorin, a folic acid derivative, is used along with 5-FU.

Because the prognosis is poor for advanced-stage CRC, these patients should be enrolled in clinical trials to possibly improve their prognosis and associated survival.

If tests show that you have cancer, you should talk with your doctor and make treatment decisions as soon as possible. Studies show that early treatment leads to better outcomes.

How treatment is planned

There are a number of factors that help your specialist plan your treatment

 
• The type and size of the cancer    
• Your general health    
• Your age    
• Whether the cancer has spread (the stage)     
• What the cancer cells look like under the microscope (the grade)

You may find other people you meet are having different treatment from you. This may be because some of the factors above are different. Or it may be because their doctor has different views to yours. Don’t be afraid to ask your doctor or nurse any questions you have about your treatment.

Treatment for colon cancer may include surgery, radiation therapy or chemotherapy, or a combination of these approaches.

Surgery - Surgery is the most common treatment for all stages of colon cancer. Depending on the stage and size of your tumor, your doctor will remove your cancer with one of the following methods:

In many cases of bowel cancer the surgeon can cut away all of the cancer.  Some people who have this treatment will be cured.  This means that their cancer never comes back.

Whether your surgeon can try to cure your cancer by cutting it all away depends on

  * The size of the cancer
  * Whether the cancer has spread (the stage) 
  * Your general health

Unfortunately, not everyone who has surgery will be cured.  Although it may seem possible to cure your cancer, your surgeon will not know the exact stage of your cancer until after you have had your surgery.  If the cancer has spread to your lymph nodes, it is possible that some cells have travelled on to other parts of the body, where they may begin to grow into secondary cancers.  To try to prevent this, you may be offered further treatment after your surgery.

If your cancer has spread to another part of your body, for example the liver or lungs, it not likely to be curable.  But treatment can often keep it under control for quite a long time. Your surgeon may not think it sensible for you to have a big operation when the cancer has already spread.  So you will probably be offered chemotherapy or radiotherapy to help control the cancer.  If the tumour in your bowel is causing symptoms, it may be sensible to operate to remove as much of it as possible (called ‘debulking’).

Local excision - This surgical approach is used for very early stage cancers. It involves inserting a tube through the rectum into the colon and removing the cancer, rather than making a cut in the abdominal wall. If the cancer is found in a polyp, the procedure is called a polypectomy.

Resection - This approach is used for larger and more advanced cancers and includes a partial colectomy, which involves removing the cancer, a small amount of surrounding healthy tissue and in many cases, nearby lymph nodes to examine for cancer. Afterwards, the doctor will sew the healthy parts of the colon together, during a procedure called an anastomosis.

Resection and colostomy - This approach is used when the ends of the colon cannot be sewn back together. In these cases, a colostomy is performed, in which an opening outside of the body for waste to pass through is created, called a stoma. A bag is then placed around the stoma to collect the waste. The colostomy may be temporary, although if the entire lower colon is removed, it is permanent. Our specially trained nurses will help you learn how to manage your colostomy and incorporate it into your lifestyle.

Laparoscopic surgery - Also called “keyhole surgery,” this innovative approach is being used for some patients with colon cancer. During the procedure, a lighted tube, called a laparoscope, and special instruments are placed inside the body through a few small incisions in the abdomen, rather than one large one. The surgeon is then guided by the laparoscope, which transmits a picture of the intestinal organs on a video monitor and then removes diseased areas of the intestines. Laparoscopic surgery for colon cancer offers an alternative and many advantages to standard surgery, including less pain and a shorter recovery period.

Radiation therapy - Radiation therapy is the use of X-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body or external radiation therapy, or from putting materials that contain radiation through thin plastic tubes, called internal radiation therapy, in the intestine area. Radiation can be used alone or in addition to surgery and chemotherapy.

Radiotherapy is not often used to treat cancer of the large bowel. But it might be used before or after surgery for rectal cancer. Sometimes radiotherapy and chemotherapy are given together for rectal cancer.  If you have a large tumour, these treatments can shrink it before surgery.  So it may be possible to completely remove the cancer, when it wasn’t before the treatment.  Or you may not need such a big operation to completely remove it. 

Radiation therapy may be used after surgery to kill any remaining areas of cancer or before surgery to shrink the tumor. Radiation also can be used to prevent cancer from coming back to the place it started and to relieve symptoms of advanced cancer.

Chemotherapy - Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by inserting a needle into a vein. A patient may be given chemotherapy through a tube that will be left in the vein while a small pump gives the patient constant treatment over a period of weeks. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the colon. If the cancer has spread, the patient may be given chemotherapy directly into the artery going to the newly infected part of the body. If the doctor removes all the cancer that can be seen at the time of the operation, the patient may be given chemotherapy after surgery to kill any cancer cells that are left. Chemotherapy given after an operation to a person who has no cancer cells that can be seen is called adjuvant chemotherapy.

Your specialist may suggest chemotherapy to try to kill any cancer cells left behind after your operation.  The doctor may call this ‘adjuvant’ chemotherapy (adjuvant means ‘alongside’).  The surgeon removes all the cancer he or she can see.  But sometimes some cells are left behind because they have escaped to surrounding tissue or to lymph nodes.  You can have adjuvant chemotherapy for tumours anywhere in the bowel or rectum.

There are several studies in the UK investigating the best type of adjuvant chemotherapy.  Patients with early tumours (Dukes A) do not need adjuvant chemotherapy.

If you have a Dukes B cancer, you may be offered adjuvant chemotherapy, possibly as part of a clinical trial.  Doctors are still not sure whether adjuvant chemotherapy reduces the risk of the cancer coming back in bowel cancers of this stage.  Some people with Dukes B may be at a higher risk of their cancer coming back, for example if cancer cells are found in blood or lymph vessels around the tumour. In this case your doctor may discuss the option of chemotherapy with you. NICE guidance says that decisions about adjuvant chemotherapy for Dukes B should be a matter of discussion between you and your oncologist.

Most people with Dukes C will be offered chemotherapy after surgery.  5FU is the chemotherapy drug most often used. You may be offered a clinical trial as several newer drugs and drug combinations are being tested to try to find a treatment that is even better than 5FU at stopping bowel cancer from coming back.

Biological treatment - Biological treatment, also called immunotherapy, tries to make your body fight against your cancer. It uses materials made by the body or made in a laboratory to boost, direct, or restore the body’s natural defenses against disease.

Radiofrequency ablation - This innovative treatment approach involves using a special probe with tiny electrodes to kill cancer cells. The probe is either inserted through an incision in the abdominal wall or directly into the skin, which only requires local anesthesia.

Cryosurgery -This treatment uses an instrument to freeze and destroy abnormal tissue.

New approaches
There are now new ways of trying to stop cancer from coming back. Some of these are in clinical trials. Doctors are investigating

  * Antiinflammatory drugs      
  * Monoclonal antibodies      
  * Vaccines

These are all experimental treatments. It will be some years before we know how effective they are.  A trial called VICTOR looked into using an anti inflammatory drug called rofecoxib (Vioxx) to help stop bowel cancer from coming back.  Unfortunately the pharmaceutical company that make rofecoxib withdrew the drug because they were concerned about side effects. So the trial was stopped early.

Search our clinical trials database for more information on trials that are open and recruiting patients.  To get there, either follow the link or click the blue clinical trials button to the left of your screen and pick ‘bowel’ from the drop down menu of cancer types.

Gregory L. Brotzman and Russell G. Robertson