Is colon cancer preventable?

Dr. Douglas Street, Contributor

Even the very thought of cancer strikes fear into most persons. There is no universal cure for it and all we have for now are various anti-cancer treatments and preventative measures, though persons have been cured of cancer. Colon cancer, fortunately, is one of those cancers that are amenable to preventative measures.

The colon is part of the gastrointestinal tract which starts at the end of the small intestine and ends at the rectum. Its primary function is to process the undigested food that leaves the small intestine to produce faeces. There are a lot of bacteria in the large intestine, and 70 per cent of the body's immune cells are there as well. The interaction between these two entities is not yet fully understood but is very important. Some of the undigested food is broken down by these bacteria and absorbed and actually, this provides about 10 per cent of the body's energy. Water, vitamins, and minerals are also absorbed from the colon.

Colorectal cancer is the third-leading form of cancer. This should not be surprising given the fact that the cells in this area multiply rapidly and are in direct contact with waste.

The symptoms of colorectal cancer include fatigue, weight loss, loss of appetite, abdominal pain (or cramps/bloating), persistent change in stool frequency and consistency, blood in the stool, and abdominal swelling. These symptoms are not specific, however.

High risks

There are some situations that increase the risk of colorectal cancer. Family history and a diet rich in fatty red meat and low in fruits, vegetables and whole grains, may also increase the risk. Colon cancer usually starts from a polyp, which is an inward growth from the wall of the colon. Conditions that increase the numbers of these growths (familial adenomatous polyposis) will increase the risk of colon cancer. Chronic ulcerative colitis of greater than eight years duration will also increase the risk.

Fortunately, there are screening methods that can greatly reduce the risk of life-threatening colorectal cancer. Starting at age 50, if there are no predisposing factors (earlier if there are), a colonoscopy should be done every 10 years, a sigmoidoscopy every five years, and a faecal occult blood annually. Polyps discovered can then be removed and tested. Daily aspirin, a healthy diet, and good lifestyle practises will also help.