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During a routine examination to check for colon cancer, Bush’s doctors found and removed five soft tumours (or polyps).
The polyps, which were immediately sent away for analysis, turned out not to be cancerous. Still, they were nevertheless of concern and President Bush will have to undergo regular colon examinations in future.
What it is
Colorectal cancer (also called colon cancer) affects the large bowel and the rectum. The colon or large bowel is about two metres in length. It is linked to the anus by the rectum, a tube approximately 20 cm long. Cancer that develops in these parts of the bowel wall is termed “colonic”, “rectal” or “colorectal”.
Most large bowel cancer, regardless of what has caused it, arises from what are called adenomatous polyps. Adenomatous is a description of the type of cell involved in the cancer. Polyps are visible as outgrowths of the surface (mucosa) of the bowel.
However, polyps are commonly found in the large bowels of middle-aged people and less than 1% of them become cancerous.
However, if an adenomatous polyp is detected by visualising the large bowel, it will be cut off biopsied) and examined under the microscope to determine whether or not it is premalignant (has the potential to spread to other parts of the body).
The rest of the bowel will also be carefully examined, since polyps seldom occur singly.
Who gets colorectal cancer?
Colorectal cancer is a common cancer in Western society, and is becoming more common in certain third world socio-economic groups that have become more westernised.
In the United States, colorectal cancer is second only to lung cancer as a cause of cancer death. In the past 40 years the incidence and mortality has not changed substantially in men, although it has declined slightly in women.
It generally affects people older than the age of 50.
How is colorectal cancer diagnosed?
If a patient has suspicious symptoms, the doctor will undertake a general medical examination, including feeling for enlarged glands and abnormalities in the abdomen. A rectal examination, by means of a gloved and lubricated finger passed through the anus, is part of the clinical examination.
A stool specimen is usually tested for the presence of concealed (“occult”) blood. A positive, occult stool test could be indicative of underlying colon cancer.
If there is a suspicion of colorectal cancer, the following special investigations may be carried out:
- Sigmoidoscopy, which involves passing a lighted tube (sigmoidoscope) through the anus into the rectum and lower colon. In this way, polyps or a cancer can be seen by the doctor. About 65% of cancers of the colon and rectum are within reach of the flexible fibre-optic sigmoidoscope.
- Colonoscopy is an extended version of sigmoidoscopy, in which the interior of the whole colon can be seen.
- Barium enema, in which x-rays of the colon and rectum are obtained after these are highlighted by means of an enema containing a solution of barium.
- A biopsy may be done if a polyp or suspicious region of the inside of the bowel is seen during colonoscopy or sigmoidoscopy. – (Health24)
A-Z of Colorectal cancer
Cancer Centre
July 2007
