Cancer of the colon is the third leading cause of cancer related deaths in the Jamaican population. In males, behind prostate, lung, breast and cervix in females. The Jamaica Cancer Registry reported an incidence of 13 per 100,000 people locally in males and females previously but this number has increased in males to 17 per 100,000 in the last five years. We are not sure why we are seeing this increase in males but it is cause for concern if it reflects a true rise in the number of cases. Like cervical cancer however, colon cancer can be prevented with screening to detect the pre- cancerous stage in the form of colon polyps. These can then be removed from the colon before cancer forms.
Cancer of the colon affects men and women in roughly equal numbers. It becomes more common the older you become; however there are certain risk factors which predispose someone to developing colon cancer at a higher rate than the average person. These risk factors include a diet high in fat and low in fibre. Smoking and a generally poor lifestyle with little or no fresh fruits and vegetables also increase your risk. If someone in the family was diagnosed with colon cancer it increases your risk as well. A family or personal history of colon polyps is another risk factor. Less common risk factors include ulcerative colitis.
Signs and Symptoms
Signs and symptoms of colon cancer are usually present when the disease is fairly advanced. For this reason it is important not to wait until symptoms start before thinking about colon cancer. Once present, symptoms include a change in bowel habit e.g. new onset constipation or persistent
diarrhoea, blood in the stools or mucous in the stools. Other signs which suggest there may be an underlying cancer are loss of appetite and unintentional weight loss. Unexplained anaemia or low blood count, especially in those over 50 is also a possible sign of colon cancer.
It is important for you to know about cancer of the colon, in particular, because there are things which you can do to actually prevent the development of the disease. Healthy lifestyle choices are important such as quitting smoking and reducing intake of red meat. Apart from this, your doctor can order tests to detect polyps before they become cancer, or detect early stages of cancer to improve your outcome. These tests range from a stool test looking for the presence of blood in the stools (which may not be obvious), to taking a picture of the bowel wall to see if anything is growing in it. The tests available to take a picture of the bowel wall are a barium enema, colonoscopy and CT colonography scan of the colon. All these tests are available locally, and your doctor will decide which test is best for you.
A Barium enema is an x-ray of the colon or large bowel using contrast to outline the bowel wall. In this way any abnormality in the bowel wall can be picked up. This test is the least expensive of the tests available to detect colon cancer or polyps.
Colonoscopy remains the single best test to diagnose colon cancer or polyps. It is an outpatient procedure and is done usually by trained gastroenterologists or in some instances trained surgeons. It examines the same area of large bowel as the barium enema but is much better at seeing the
exact cause of the problem and in addition allows the doctor to either completely remove any polyps before they become cancerous at the same time or to do biopsies of any suspicious areas in the bowel wall. A light sedative is always used with colonoscopy making the procedure very comfortable.
CT Colonography is another way of looking at the bowel for signs of cancer. It uses computer software to build a 2D or 3D picture of the colon allowing specially trained radiologists or other specialists to pick up polyps or cancer as well. It is far better than a barium enema and at least as good as a colonoscopy but carries the disadvantage of not allowing biopsies .Therefore any abnormal results must again be followed by a colonoscopy.
It is recommended that everybody who is over the age of 45 should have a screening test for colon cancer. This is whether or not you have symptoms or signs of bowel problems. If a relative of yours has had cancer of the bowels it is even more important for you to have a screening test done, and this should be 10 years before your relative was diagnosed or age 45, whichever is earlier. These tests are done as outpatient tests and so you do not have to be admitted to hospital to do them.
Cancer of the colon is quite common locally and the numbers diagnosed each year continue to increase, but the good thing is that by screening tests you can prevent the disease in most cases and catch it early in others. We must do all we can to fight against colon cancer by screening for this potentially preventable disease.