Bowel cancer (also known as colon, or colorectal, cancer) is still one of the most common forms of cancer affecting Australians. The good news is that there are steps we can all take to help avoid this disease, or at least catch it early on when cure is still possible.
Step 1: Lifestyle
Bowel cancer risk is significantly affected by lifestyle. It is estimated that improvements in diet and physical activity could reduce the incidence of bowel cancer by up to 75 per cent.
A diet that is high in fat and low in fibre has been linked with a higher risk of bowel cancer. So by limiting your intake of saturated fat, you can help reduce your risk. That means going easy on cakes, biscuits, pies and take-away food as well as full-fat dairy products. The Cancer Council Australia also recommends limiting your intake of red meat to 3-4 times per week, and avoiding processed meats.
On the other hand, by increasing your intake of foods such as fruits and vegetables, you can help prevent bowel cancer. This is because as well as being high in fibre, fruits and vegetables contain lots of the vitamins, minerals, phytochemicals and antioxidants that are thought to be powerful anti-cancer agents. Try to eat at least 5 serves of vegies and 2 serves of fruit every day.
Alcohol and smoking
Drinking excessive amounts of alcohol can increase the risk of some cancers, including bowel cancer. Keeping your alcohol intake down can help reduce your risk and improve your health in general.
Most people know that smoking is bad for their health. It increases the risk of many types of cancer, and bowel cancer is no exception. Researchers have also found that among people who have been diagnosed with bowel cancer, smoking increases the risk of dying of the disease.
Having a sedentary lifestyle also seems to increase your risk of developing bowel cancer. Exercising for just 30 minutes on most days can reduce this risk by keeping you active and helping to keep your weight under control.
Step 2: Screening tests
What is a screening test?
Many cancers, including bowel cancer, don't cause any symptoms at first. Screening tests can be used to detect early bowel cancer in people who don't have any symptoms, when there is a much better chance of a cure.
Screening for bowel cancer
Because your risk of bowel cancer is fairly low when you are young, most people don't need to have any screening tests until they reach middle age. The National Health and Medical Research Council recommends that for the majority of people, a test known as a faecal occult blood test should be done at least once every 2 years after you've turned 50.
However, there are some people who have a higher than average risk of bowel cancer (e.g. people with inflammatory bowel disease, certain genetically defined cancer syndromes, or a family history of colon cancer), and these people may need to be screened from an earlier age. If you are at increased risk of bowel cancer, you should discuss screening options with your doctor.
Faecal occult blood tests
Small bowel tumours and polyps (small outgrowths that can turn into cancer over time) can bleed into the bowel, but often don't bleed enough for you to notice. A faecal occult blood test (FOBT) can be used to detect small amounts of blood in your bowel movements (faeces).
For this test, you collect small samples of your faeces at home, which are then tested in the laboratory for traces of blood. There are also newer types of FOBT that may be easier to perform, which involve testing the toilet water above the surface of the stool in the toilet bowl.
If the FOBT detects traces of blood, your doctor will recommend you have another test — usually a colonoscopy. This is because the FOBT cannot tell whether it is bowel cancer or another problem that has caused the bleeding. While cancer is not the most common cause of a positive test, it needs to be ruled out.
You can get testing kits (which cost about 30 dollars) from your doctor or pharmacist. Once a year, Rotary runs a bowel screening programme called Bowelscan. This programme normally runs for a week sometime between March and August (depending on where in Australia you live), when screening kits and testing are available for a cheaper price.
The National Bowel Cancer Screening Program is a government programme that offers free faecal occult blood testing each year to those people turning 50, 55, 60 and 65. This will be expanded in 2015 to include those turning 70, and then further expanded to offer 2-yearly FOBT screening to all Australians aged 50 to 74 years.
A colonoscopy is a test that allows your doctor to carefully examine your entire large bowel. This test uses a special instrument called a colonoscope, which is a thin, flexible tube with a tiny camera on the end of it. The colonoscope gives your doctor a clear view of the inside of your bowel. It is the most effective test for detecting tumours and polyps, and polyps can also be removed during the test.
A colonoscopy is usually performed in a hospital or clinic, and the test usually takes about 30 minutes. You will be sedated during the test. In preparation for the test, you need to eat a restricted diet and drink a solution to clean out your bowel.
Benefits of screening
Regular screening is the best way of catching the disease at a stage when it can be cured. When bowel cancer is diagnosed early, the chance of successful treatment is about 90 per cent. Compare that with more advanced cases, where the cure rate is about 50 per cent or lower.
It is estimated that population-based screening programmes for bowel cancer using FOBT can reduce deaths from bowel cancer by up to a third.