Risk Factors

The American Cancer Society lists a number of risk factors for colorectal cancer. A risk factor for a cancer is anything that increases your chances of developing that cancer. Some of these risk factors are under your control; others aren't. Risk factors include:

• Smoking: Smokers are 30 to 40 percent more likely than nonsmokers to die from colorectal cancer. Smoking may cause up to 12 percent of fatal colon cancers. Some of the cancer-causing chemicals in tobacco reach the colon after being swallowed while others are absorbed into the bloodstream to be delivered to distant parts of the body.
• Aging: More than ninety percent of cases of colorectal cancer occur in people over 50.
• A diet of mostly animal sources: A diet high in fat from animal sources increases the risk of colon cancer. The American Cancer Society recommends choosing at least 5 servings of fruit and vegetables every day, as well as eating several servings of grain products and/or beans.
• Physical inactivity: Inactivity increases the risk of developing colon cancer.
• Obesity: Being very overweight increases the risk of dying from colon cancer.
• Diabetes: People with diabetes have a 30 to 40 percent increased chance of developing colorectal cancer, as well as an increased death rate.
• Alcohol intake: Heavy use of alcohol increases the risk of colorectal cancer.
• A family history of colorectal cancer: If you have a close relative (parent, sibling, offspring) who has had colorectal cancer, your risk of colorectal cancer is increased. Two or more close relatives with the disease raise your risk even higher. There may be an inherited tendency toward this type of cancer.
• Familial colorectal cancer syndromes: Familial adenomatous polyposis is a disease in which people develop hundreds of polyps in the colon and rectum. This may happen anywhere between age five to age 40. Cancer usually develops in one or more of these polyps by age 20. By age 40, cancer is almost certain to develop without preventive surgery. Three or four percent of colorectal cancers are caused by this disease. This type of colorectal cancer is inherited, and other family members will probably have developed this cancer prior to age 50.
• Ethnic background: Jews of Eastern European decent appear to have a higher rate of colorectal cancer.
• A personal history of colorectal cancer: Once you have had colorectal cancer, especially if it occurred before age 60, you are more likely to develop another colorectal cancer.
• A personal history of colorectal polyps: If you have a polyp, this indicates that your risk of developing colorectal cancer is increased.
• A personal history of inflammatory bowel disease: This disease, including Crohn's disease and chronic inflammatory bowel disease, increases your chance of developing colorectal cancer.