Every one of us is at risk for colorectal cancer. One out of every 50 people, or 2% of the population, will get colorectal cancer. The majority of people who develop colorectal cancer have no known risk factors.

Although the exact cause of colorectal cancer is not known, there are some factors that increase a person's risk of developing the disease. These include:

• Age. The risk of developing colorectal cancer increases as we age. The disease is more common in people over 50, and the chance of getting colorectal cancer increases with each decade. However, colorectal cancer has also been known to develop in younger people.
• Gender. Women have a higher risk for colon cancer, while men are more likely to develop rectal cancer.
• Polyps. Polyps are non-cancerous growths on the inner wall of the colon or rectum. While they are fairly common in people over 50, one type of polyp, referred to as an adenoma, increases the risk of developing colorectal cancer. Adenomas are non-cancerous polyps that are considered precursors, or the first step toward colon and rectal cancer.
• Personal history. Research shows that women who have a history of ovarian, uterine or breast cancer have a somewhat increased risk of developing colorectal cancer. Also, a person who already has had colorectal cancer may develop the disease a second time. In addition, people who have chronic inflammatory conditions of the colon, such as ulcerative colitis or Crohn's disease, also are at higher risk of developing colorectal cancer.
• Family history. Parents, siblings, and children of a person who has had colorectal cancer are somewhat more likely to develop colorectal cancer themselves. If many family members have had colorectal cancer, the risk increases even more. A family history of familial polyposis, adenomous polyps, or hereditary polyp syndrome also increases the risk.
• Diet. A diet high in fat and calories and low in fiber may be linked to a greater risk of developing colorectal cancer.
• Lifestyle factors. You may be at increased risk for developing colorectal cancer if you drink alcohol, smoke, don't get enough exercise, and if you are overweight.
• Diabetes. People with diabetes have a 30-40% increased risk of developing colon cancer.

Having one or more of these risk factors does not guarantee that you will develop colorectal cancer. However, you should talk about these risk factors with your doctor. He or she may be able to suggest ways to reduce your chances of developing colorectal cancer.