Colon Cancer Risk Factors

The exact cause of colorectal cancer is not known. However, studies show that certain factors are linked to an increased chance of developing the disease. Ongoing research will continue to give us information in the diagnosis and treatment of colorectal cancer.

Who's at risk?

There are a number of personal factors influencing who is more likely than others to develop colon or rectal cancer.

1. Age - Colorectal cancer is more likely to occur as people get older. The average age for developing colorectal cancer is around 50, but risk can begin as early as 40.
   
2. A history of cancer - A person who has already had colorectal cancer is at an increased risk of developing it a second time. Women with a history of ovarian, breast, or uterine cancer have a somewhat increased chance of developing colorectal cancer.
   
3. A history of polyps - Polyps are growths that protrude from the inner wall of the colon or rectum. They are relatively common in people over age 50. Most are benign (noncancerous). However, some kinds of polyps are more likely to result in the development of cancer than others. Adenomatous polyps are considered the most likely to develop into cancer. The procedure to remove polyps, and the earlier the better, is called a polypectomy.
   
4. A history of inflammatory bowel disease - Ulcerative colitis is a condition that causes inflammation and sores (ulcers) in the lining of the colon. Crohn's colitis (also called Crohn's disease) causes chronic inflammation of the gastrointestinal tract, most often the small intestine. People who have ulcerative colitis or Crohn's colitis may be more likely to develop colorectal cancer than people who do not have these conditions.
   
5. Race - African Americans are at greater risk of developing colon cancer and of dying from the disease than any other racial or ethnic group in the United States.

Risk factors linked to family

1. Family history - You are at increased risk if you have a first-degree relative (father, mother, brother, sister) with a history of either colon cancer or polyps before age 60; or two or more relatives at any age.
   
2. Familial adenomatous polyposis (FAP) - This is a rare, inherited condition in which hundreds of polyps develop in the colon and rectum. This condition can appear as early as the teen years and is very likely to lead to colorectal cancer.
   
3. Gardner's syndrome - Like FAP, this hereditary condition results in polyps and colon cancer that develops at a young age. It can also cause noncancerous tumors of the skin, soft connective tissue, and bones.
   
4. Hereditary nonpolyposis colorectal cancer (HNPCC) - People with this hereditary condition tend to develop cancer at a young age without first having many polyps.
   
5. Ashkenazi Jews - These are Jews from, or whose ancestors are from, Eastern Europe. They have an inherited change in their DNA that causes a slightly increased risk of developing colon cancer
   

Lifestyle risk factors

1. Smoking - Recent studies show that smokers are 30 - 40 percent more likely than nonsmokers to die of colorectal cancer.
   
2. Diet - Some evidence suggests that the development of colorectal cancer may be associated with certain food characteristics.  Among populations that consume a diet high in fat, protein, calories, alcohol, and meat (both red and white) and low in foods with fiber, calcium and folate (folic acid), such as whole grains, fruits, and vegetables are at higher risk for colorectal cancer.
   
3. Exercise - Some evidence suggests that being overweight and living an inactive lifestyle may be associated with an increased risk of colorectal cancer. In contrast, people who exercise regularly may be at lower risk.
   
4. Alcohol - Heavy use of alcohol has been linked to colorectal cancer.