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Risk Factors and Protective Factors for Colorectal Cancer


Risk factors for colorectal cancer

It is known that environmental and genetic factors can influence one’s risk for developing colorectal cancer (CRC). Knowing that a family member has been previously affected by the disease in the past and that an inherited risk may have been passed on to oneself is probably the most important risk factor for developing CRC. This is why it is important to keep track of family members and any medical conditions that they have been labeled with such as Familial adenomatous polyposis (FAP syndrome) and Lynch syndrome (Hereditary nonpolyposis colorectal cancer). Together these two conditions make up about 5% of all CRC cases. Patients who have a personal history of CRC or adenomatous colon polyps are at an increased risk for the future development of colon cancer.

Having a history of inflammatory bowel disease such as ulcerative colitis (UC) or Crohn’s disease is associated with an increased risk of CRC.  In UC patients, the increased risk of developing CRC can be as high as 30% by the fourth decade of living with the disease. Certain races such as African American are felt to be at an increased risk so screening for this group starts at a younger age (age 45 instead of age 50). A prior history of abdominal radiation or prior organ transplants due to long term immunosuppression have also been linked to an increased frequency of CRC. Some other documented risk factors for developing CRC include obesity, diabetes, a diet high in red meat or processed meats, cigarette smoking, and alcohol consumption. The average person has a 4.5 percent lifetime risk of developing colorectal cancer with 90 percent of these cancers occurring after age 50. CRC risk increases with age throughout life.

Protective factors against CRC

Knowing the risk factors is important but also knowing that there are possible protective factors is also important. Participating in regular physical activity, maintaining a diet high in fruits, vegetables, and fiber  are all felt to be beneficial in decreasing one’s risk for developing CRC.  The consumption of fish oil (Omega 3 Fatty acids), coffee, garlic, calcium and vitamin D may  have protective roles as well.  In certain conditions, such as Lynch syndrome, taking aspirin therapy can be used in selected patients for chemoprevention of Lynch syndrome-associated colon cancers.

This Colon Cancer awareness month, I urge you to learn more about your own risk for developing CRC and incorporate protective factors including healthy eating and exercise into your daily lives. If you have questions, speak to your physician today, so that you can lower your risk for CRC.

- Anthony J. Nici, MD | Gastroenterology