- Age is the most important risk factor for getting colorectal cancer. Colorectal cancer is more common in people over age 50.
- Personal History - people with a history of colorectal cancer or polyps, or inflammatory bowel disease (such as ulcerative colitis and Crohn's disease) are more likely to develop colorectal cancer.
- Family history of colorectal cancer or polyps: If you have close relatives who have had this cancer, your risk might be increased. This is especially true if the family member got colorectal cancer or polyps before age 60.
- People with certain inherited diseases (familial adenomatous polyposis and hereditary nonpolyposis colon cancer) are more likely to get cancer of the colon and rectum.
- Race or ethnic background: Some racial and ethnic groups such as African Americans and Jews of Eastern European descent (Ashkenazi Jews) have a higher colorectal cancer risk. All of the reasons for this are not yet understood.
- Diets high in red meats and processed meats increase a person's risk for getting cancer of the colon and rectum, while a diet high in vegetables, fruit and fiber may reduce risk.
- Being overweight, leading an inactive lifestyle, smoking and heavy alcohol use also may increase risk.
- Diabetes: People with Type 2 diabetes have an increased chance of getting colorectal cancer. They also tend to have a higher death rate from this cancer.
While we do not know the exact cause of most colorectal cancers, there are certain known risk factors: