Colorectal Cancer FAQ

• What is bowel cancer?

  Bowel cancer is an uncontrolled growth in a cluster of cells from the lining of the colon (large bowel) or rectum. These cells spread into surrounding tissues and can travel to other parts of the body through lymphatic channels and blood vessels.
  

• Why does bowel cancer occur?

  Bowel cancer occurs when damage to the genes of cells lining the colon results in a loss of control of cell growth. This uncontrolled growth produces a lump (or “polyp”) in the lining of the bowel which can eventually progress to a cancer.
  

• Who gets colon cancer?

  New Zealand has one of the highest rates of colon cancer in the World. One in fifteen New Zealanders get colon cancer. Some of the genetic abnormalities that result in colon cancer can be inherited. If you have one first degree relative with colon cancer, your risk is nearly doubled. If you have two first-degree relatives with colon cancer your risk is nearly trebled. Despite this, most people who get colon cancer do not have any relatives with the disease.
  

• Can I prevent colon cancer by eating carefully?

  While there is some evidence that a diet high in fresh fruit and vegetables and low in animal fats may reduce your risk of colon cancer and a number of other diseases, no diet can completely eliminate your risk of colon cancer.
  

• How do I know if I have colon cancer?

  Colon cancer usually does not cause any symptoms until it has been present for some time. Once the tumour is of sufficient size, it can cause symptoms such as bleeding or anaemia, change in bowel habit or blockage of the bowel. Cancer rarely causes pain unless it has grown through the wall of the bowel. By this time, the cancer is usually at an advanced stage.
  

• Can colon cancer be prevented?

  Yes. More than 95% of colon cancers begin as a benign (non-cancerous) growth in the lining of the colon called an adenomatous polyp. Except in people with a large inherited risk or with ulcerative colitis, these polyps usually take several years to progress into cancer. If they are found and removed before this occurs, cancer will not develop.
  

• How do I know if I have colonic polyps?

  The vast majority of colonic polyps cause no symptoms at all. Occasionally they will cause a small amount of bleeding or mucus. The only way to know if you have polyps is to look for them.
  

• How are polyps found and removed?

  Polyps are found with an examination called colonoscopy. A flexible tube with a tiny video camera on the end is passed around the colon under mild sedation. Polyps are seen on a TV monitor and can be removed at the same time through the colonoscope.
  

• Should I have a colonoscopy?

  You should have regular colonoscopy if you have more than one first degree relative with colon cancer or polyps, or if you have ulcerative colitis. You should also have a regular colonoscopy if you have had polyps or colon cancer in the past,or symptoms.
  

• Will I die if I get colon cancer?

  The majority of people with colon cancer can be cured. The earlier the cancer is detected the greater the chances of cure. Once the cancer has spread beyond the colon, cure becomes more difficult but modern treatment can result in significant prolongation of good quality life, or occasionally cure, even in this situation.
  

• How is colon cancer treated?

  The primary cancer in the colon is treated by surgical removal of the section of colon involved by the cancer. Usually it is possible to join the ends of the colon together. Very occasionally it may be necessary to create a colostomy where the colon comes onto the abdominal wall into a bag. Generally this is only necessary for cancers very close to the anus. In some circumstances, surgical excision is proceeded or followed by a course of chemotherapy or radiotherapy.

Relevant Links

Colorectal Cancer Screening
Colonoscopy
Endoscopy