Colorectal Cancer
Prevention
Fairly simple screening tests can prevent colorectal cancer. Screening tests look for a certain disease or condition before any symptoms appear. Regular screening is recommended at age 40 or earlier for people who have a high risk of colorectal cancer and beginning at age 50 for everyone else.
The following guidelines are for people who do not have an increased risk for colorectal cancer.
Colorectal screening guidelines Test Frequency Fecal occult blood test (FOBT)*
Every 1 to 2 years
or
Every 5 years
or
Every 5 years
or
Every 10 years
*Some groups recommend combining a yearly FOBT with a sigmoidoscopy every 5 years.
You will need to begin routine screening earlier than age 50 and have it more often if you have a higher risk for colorectal cancer.
Virtual colonoscopy (also called computed tomographic colonography or CT colonography) uses X-rays and a computer to take pictures of the inside of your large intestine. It may be used as a screening test for people who do not have an increased risk for colon cancer. For people who have increased risk, regular colonoscopy may be better because it allows your doctor to remove polyps (polypectomy) and take tissue samples during the screening procedure. Studies are promising, but virtual colonoscopy is still not proved to be consistent and reliable. Virtual colonoscopy is not widely available, and the cost may not be covered by provincial health plans or private health insurance.8, 9
Here are other things you can do to help prevent colorectal cancer:
- Watch your weight. In trials, people who were overweight got colorectal cancer more often than those who were not. And people whose extra fat was in the waist area got it more often than people whose extra fat was in the hips or thighs. For more information, see the topic Healthy Weight.
- Eat well. Eat a variety of healthy foods, especially fruits and vegetables. Eating more vegetables, fruits, legumes, fish, poultry, and whole grains helps prevent cancer. Limit your consumption of animal fat. Take a calcium supplement daily. For more information, see the topic Healthy Eating.
- Limit drinking. People who drink more than 2 alcoholic drinks a day—and especially those who drink more than 3 drinks a day—have a slightly higher risk for colorectal cancer.6
- Get active. Keep up a physically active lifestyle. Being fit also leads to an improved sense of well-being, improved appearance, and increased stamina and strength. For more information, see the topic Fitness.
- Do not smoke. Smokers have a higher rate of cancer than non-smokers.2 For more information, see the topic Quitting Tobacco Use.
Researchers continue to investigate ways to use drugs to prevent cancer. Drugs being studied include hormones used to treat symptoms of menopause, a mineral called selenium, and vitamin E.
What to think about
If you have a strong family history of colon cancer, you may want to talk to your doctor or a genetic counsellor about having a blood test to look for changed genes. Genetic testing can tell you whether you carry a changed, or mutated, gene that can cause colon cancer. Having certain genes greatly increases your risk of colon cancer.
You have a strong family history if each of the following is true:
- You have at least three relatives who have had colon cancer, and at least one of them is a parent, brother, or sister.
- Those relatives are spread over two generations in a row (for example, a parent and a grandparent).
- One of those relatives got cancer before age 50.
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| Author: | Douglas Dana Shannon Erstad, MBA/MPH | Last Updated: March 19, 2007 |
| Medical Review: | Adam Husney, MD - Family Medicine Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology Arvydas D. Vanagunas, MD - Gastroenterology | |
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