Colon Cancer Health Center

These risk factors don’t determine who does and doesn’t develop the disease. Some people with colorectal cancer have no known risk factors. Likewise, people who have strong risk factors don’t necessarily experience it.

This means everyone needs to be careful about screening for colorectal cancer, starting at age 50, or earlier if you have a family history of the disease. Talk to your doctor about the best screening schedule for you based on your individual health and family history.

Here are the major factors that can increase your colorectal cancer risks:

• Age over 50. Colorectal cancer is more likely to occur as people get older.
• More than 90 percent of people with this disease are diagnosed after age 50.
• The average age at diagnosis is 72.
• Colorectal polyps. Polyps are growths on the inner wall of the colon or rectum, which are common in people over age 50.
• Most polyps are benign (not cancer), but some polyps (adenomas) can become cancer.
• Finding and removing polyps may reduce the chance of colorectal cancer developing.
• Family history of colorectal cancer. If you have close relatives (parents, brothers, sisters or children) with a history of colorectal cancer, you are somewhat more likely to develop this disease.
• Personal history of cancer. If you have already had colorectal cancer, the disease can return. Also, women with a history of cancer of the ovary, uterus (endometrium), or breast are at a somewhat higher risk of developing colorectal cancer.
• Ulcertive colitis or Crohn's disease. Having a condition that causes inflammation of the colon (such as ulcerative colitis or Crohn's disease) for many years increases the risk of developing colorectal cancer.
• Diet. Studies suggest that diets high in fat (especially animal fat) and low in calcium, folate and fiber may increase the risk of colorectal cancer.
• Some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer.
• Cigarette smoking. Smoking cigarettes may increase the risk of developing polyps and colorectal cancer.
• Genetic alterations. Changes in certain genes increase the risk of colorectal cancer.
• Hereditary nonpolyposis colon cancer (HNPCC) is the most common type of inherited (genetic) colorectal cancer, accounting for about two percent of all colorectal cancer cases.
• It is caused by changes in an HNPCC gene.Familial adenomatous polyposis (FAP) is a rare inherited condition in which hundreds of polyps form in the colon and rectum.