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Bowel Cancer What is bowel cancer? Cancer of the large bowel (colon and rectum) is the most common internal cancer in Australia affecting approximately one in twenty-five Australians and is referred to as bowel or colorectal cancer. Cancer of the small bowel (small intestine) is quite uncommon. The large intestine is a muscular tube 1-2 metres in length, and the rectum is the last 15cm, and this leads to the anal canal which is 3cm long leading to the outside of the body. Bowel cancer is a malignant tumour which generally begins in the lining of the bowel. Untreated it will increase in size protruding into the lumen of the bowel and may cause blockage or can ulcerate leading to blood loss and anaemia. It may also spread through the wall of the bowel to invade adjacent organs and may also disseminate and spread via the blood stream, and another draining symptom referred to as the lymphatic system. In this way secondary cancers can develop in other organs, such as the liver. When a bowel cancer is diagnosed early then there is an excellent chance of being completely cured. If the disease is widely spread throughout the body, it may be impossible to effect a cure, but the disease may still be controllable. The cause of bowel cancer is likely to be a combination of genetic or inherited factors plus environmental influences. It is suggested that a high animal fat, high animal protein diet may be associated with an increased incidence of bowel cancer, and that if perhaps there was an increased amount of fibre, the incidence may be less. Research into the causes of bowel cancer is continuing. Most bowel cancers occur in people over the age of 50, but no age group is immune. People with special risks include the following. 1. Patients with previous bowel cancer or bowel polyp Polyps are benign (innocent) growths on the lining of the bowel, which may resemble a small mushroom. The polyps, which are a particular risk, are referred to as "adenomas". It is currently believed that almost all bowel cancers start off as benign polyps. Most of these can be removed quite easily during a procedure referred to as colonoscopy. Any patient who has had a previous bowel cancer is much more likely than the remainder of the community to develop another unrelated bowel cancer. 2. Family history of Multiple Familial Polyposis Multiple Familial Polyposis is an inherited condition where the lining of the bowel contains hundreds of polyps. It is a rare condition, but people who are affected by the disease if untreated will develop bowel cancer. 3. HNPCC Hereditary Nonpolyposis Colorectal Cancer (HNPCC) is a condition in which the propensity to develop colorectal cancer is inherited. "Nonpolyposis" means that colorectal cancer can occur when a small number of polyps are present (or polyps are not present at all). In families with HNPCC, cancer often occurs at a younger age than colorectal cancer which is not inherited and usually occurs on the right side of the colon. 4. Family history of bowel cancer The lifelong risk of bowel cancer for the average Australian is one in twenty-five. This incidence will be doubled if a first degree relative (parent, brother, sister or child) develops bowel cancer. There is also an increased risk if a first degree relative has had a bowel polyp. 5. Long-standing inflammation of the bowel Long-standing, chronic inflammation of the bowel (ulcerative colitis) may be associated with a markedly increased incidence of cancer after the condition has been present for 8-10 years. What can be done to reduce the risk of developing bowel cancer? In general screening is not recommended in Australia for those individuals who do not have any special high risk factors. Nevertheless, for the groups mentioned above, some form of surveillance programme is appropriate. Surveillance may mean regular testing of the bowel actions to detect blood, but these tests to this time are unreliable in that false negative and false positive results are not uncommon. Many authorities believe that regular colonoscopy is the most appropriate way to proceed and you may have received separate information on this subject. One reasonable programme, which I endorse, may be colonoscopy performed on a 3 yearly basis. What symptoms may suggest bowel cancer? Bleeding or mucus at the time of having a bowel action changes in the normal pattern of bowel activity, abdominal discomfort and a weakness or unexplained weight loss. It is wise to examine the faeces for blood after evacuation of the bowel, but agents, which color the toilet, may make this difficult and therefore may be better avoided. Very small and early bowel cancer can sometimes be removed using the colonoscope or other instruments via the anus. In most instances however a formal operation with removal of a segment of the bowel is required. In some instances additional chemotherapy or radiotherapy may be required. When a surgical procedure is performed, usually a segment of the bowel is removed in association with adjacent lymph glands. In the vast majority of cases, the bowel can be joined together and there is no requirement for an artificial opening (stoma) where the faeces comes away into a bag or appliance. In some instances a temporary artificial opening may be necessary but sometimes it may need to be permanent. If such a stoma is necessary, then a modern reliable appliance is worn which ensures an excellent quality of life for those who require them. Highly qualified nursing staff (stoma therapists) teach and supervise the management of stoma (artificial opening) appliances. Related Downloads
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