There is no single cause for developing colorectal cancer, however, there are some individuals who are considered to be at a higher risk than the general population. Some of the more common risk factors believed to be associated with the development and diagnosis of colon or rectal cancer are list below:
- Age: the vast majority of people diagnoses with colon or rectal cancer are older than 50 years of age. Colon or rectal can still develop in the younger population, but it occurs much more infrequently.
- Personal History of Colorectal Cancer: If you have previously been diagnosed with colon cancer or had adenomatous polyps removed, there is an increased risk of once again developing colon cancer in the future.
- Family History of Colorectal Cancer: A family history of colorectal cancer means that one or more close blood relatives have or had colorectal cancer. Some families have more cases of colorectal cancer than would be expected by chance. In families with a history of colorectal cancer the risk is increased if:
- A first degree relative (parent, sibling, or child) has had colorectal cancer. The risk is further heightened if the first degree relative had colon cancer than if the first degree relative had rectal cancer.
- More than one first degree relative has had colorectal cancer
- Colorectal cancer was diagnosed in a family member under the age of 50.
- Inflammatory Intestinal Conditions: It is believe that chronic inflammatory conditions of the colon such, as ulcerative colitis (UC) and Crohn’s disease create an increased risk of developing Colon Cancer.
- Inherited Syndromes: Genetic syndromes which are passed through generations of a family may increase the risk of colon or rectal cancer. These syndromes include Familial Adenomatous Polyposis (FAP) and Hereditary Nonpolyposis Colorectal Cancer (commonly known as Lynch Syndrome).
- Polyps: Either a personal or family history of polyps in the colon, rectum, or both significantly increased the risk of developing colorectal cancer. Adenomatous Polyps (Adenomas) carry the potential to becoming cancer. The risk of developing cancer from adenomatous polyps is variable towards the type, size and number of polyps.
- Sedentary Lifestyle: A relatively inactive lifestyle has been proven to heighten the chances of colorectal cancer.
- Diabetes: Individuals with diabetes and insulin resistance may have an increased risk of colon cancer.
- Diet: Diets which are low in fiber and/or high in fat may be associated with the development of colon and rectal cancer.
- Smoking: people who smoke cigarettes may have a heightened risk towards colon cancer.
- Obesity: Colorectal cancer appears to occur more frequently in people who are overweight or obese than in those who are a healthy weight. Having a higher BMI increased the risk of developing colorectal cancer in both men and women.