Colorectal Cancer Risk Factors

Studies have shown that having certain risk factors can make people more likely to develop colorectal cancer. These risk factors include the following (in no particular order):

• Age: Over 90% of people diagnosed with colorectal cancer are older than age 50.
• Family history: People with a close relative (parent, brother, sister, child) who had colorectal cancer before age 60, or two or more close relatives who had the disease at any age, are at higher risk of developing colorectal cancer.
• Personal history: People who have already had colorectal cancer are at risk of developing it again.
• Intestinal polyps: Having large or many polyps puts people at an even greater risk of colorectal cancer.
• Genetic alterations: People with changes in certain genes are more likely to develop colorectal cancer. Common types of inherited (genetic) colorectal cancer are:

• Hereditary nonpolyposis colon cancer (HNPCC), the most common type. HNPCC accounts for about 2% of all colorectal cancer cases and is caused by changes in a specific gene.
• Familial adenomatous polyposis (FAP). FAP is caused by a change in a specific gene called APC and accounts for less than 1% of all colorectal cancer cases.
• Family members of people with HNPCC or FAP can have genetic testing to check for specific genetic changes.

• Diet: People who eat mostly foods that are high in fat, especially from animal sources, are at higher risk of colorectal cancer. (It is recommended that individuals consume plenty of fruits, vegetables and whole grain foods, and limit intake of high-fat foods.)
• Physical activity: People who do not exercise enough or are very overweight are more likely to develop colorectal cancer.
• Cigarette smoking/alcoholism: Smokers or people with a history of alcoholism may be at an increased risk of developing colorectal cancer.

Discuss any colorectal cancer risk factors you may have with your doctor. Learn more about screening and diagnosis of colorectal cancer.