Bowel cancer (also known as colon cancer) is the most common internal cancer in Australia after prostate cancer in men and breast cancer in women, and is the leading cause of cancer death in non-smokers. With more than 10,000 new cases reported annually, it affects approximately one in 20 Australians. The incidence of bowel cancer starts to rise after age 40 and the risk continues to increase with age.
The good news is that colon cancer can be cured if detected early.
What causes bowel cancer?
There is no one cause, but studies show that a diet high in animal protein, saturated fat and beer is associated with high rates of colorectal cancer. While you can't completely prevent any cancer, The Cancer Council of Australia believes around 25 percent of bowel cancers diagnosed in Australia every year could be prevented if men and women ate a healthy diet, maintained a healthy weight and exercised regularly.
The development of bowel cancer takes many years. It starts on the inside wall of the bowel and can grow there before spreading to other parts of the body. Often very small amounts of blood, not visible to the naked eye, are leaked from these cancers long before any symptoms develop. This blood is then passed into the faeces.
The majority of bowel cancers develop from polyps, tiny growths inside the colon or rectum. Most bowel polyps are not cancerous and most do not cause any symptoms. However, if you can detect them and have them removed, the risk of bowel cancer is reduced.
What are the symptoms?
In many cases, there may be no symptoms at all. Yet there can be telltale signs and symptoms that need to be checked out by a doctor.
Never ignore the following:
- rectal bleeding blood in the toilet bowl, on the toilet paper or in the stools
- diarrhoea, especially if persistent
- constipation, especially if persistent
- a change in bowel habits
- persistent colicky pain
You should see your doctor as soon as possible if you have symptoms suggesting possible bowel cancer. Like all cancers, the earlier it can be treated the better your chances are of beating it.
Are you at risk?
No one knows why cancer affects some people and not others. However, your risk of bowel cancer increases two to four times if:
- You have one of more close relatives (mother, father, sister, brother, child) who have had bowel cancer or polyps.
- You have already had bowel cancer or polyps.
- You have had extensive ulcerative colitis.
If you are in any of these groups, the Gut Foundation recommends seeing your doctor and asking about a Bowel Cancer Prevention Program based on surveillance colonoscopy.
Early bowel cancer can be cured by removing the tumour and the sections of the intestine on both sides of it. Nearby lymph nodes will also be removed to see if they harbour cancer cells. Chemotherapy and/or radiation treatments are often given after surgery.
What you can do
Healthy eating and regular physical activity can help lower your risk of cancer.
To minimise the risk of bowel cancer you should:
- Eat less fat, especially saturated fat which is found in most animal products including meat, poultry and full-cream milk and butter. Some research has suggested that diets high in red meat are associated with a slight increase in risk of bowel cancer; processed meat seems to be of most concern.
- Eat more high-fibre foods such as wholegrain breads and cereals wholegrain foods contain high levels of fibre, resistant starch and natural protective substances such as antioxidants.
- Eat a variety of fruits and vegetables they contain natural substances that can destroy cancer-causing agents (carcinogens). Five serves of vegetables and two serves of fruit a day are recommended for good health and reducing the cancer risk.
- If you drink alcohol, do so in moderation.
- If you smoke, stop.
- Exercise regularly and maintain a normal weight.
- Ensure a good intake of calcium.
And remember ...
- Early diagnosis and removal of polyps is important.
- Check if you are in a high-risk group.
- Do not ignore rectal bleeding.