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Risk Factors for Colorectal Cancer

  • Michelle Badash, MS
Publication Type:

Condition InDepth

Risk Factors for Colorectal Cancer

A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to develop colorectal cancer with or without the risk factors listed below. However, the more risk factors you have, the greater your chance of developing colorectal cancer. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.

Generally, colorectal cancer is found more often in men than in women. Specifically, women have higher rates of colon cancer, while men have higher rates of rectal cancer. Colorectal cancer can develop at any age, but is more likely found in those aged 65 years and older. Risk typically increases starting at age 50.

Other factors that may increase your chance of colorectal cancer include:

Genetic Factors

Heredity is perhaps the strongest risk factor for developing colorectal cancer. It is estimated that approximately 20% of all cases of colorectal cancer are hereditary. This risk increases if you have a primary relative, such as a parent, sibling, or child who develops colorectal cancer.

Hereditary colon cancer occurs at a younger age. As a result, anyone with a history of colon cancer in a relative should seek screening early. Guidelines recommend a screening at age 40 or 10 years younger than the earliest age at which a relative developed colon cancer, whichever is younger. With inherited forms of colon cancer, the presence of the disease before age 60 in near relatives increases one’s own risk.

The 2 most common forms of inherited colon cancer are:

  • Lynch syndrome—This is a fast-growing form of colorectal cancer. It accounts for about 5% of all colorectal cancer cases. Typically, people with this form develop cancer in their 40s.
  • Familial adenomatous polyposis (FAP)—People with this type of colorectal cancer develop hundreds of polyps at a very young age, sometimes as early as their teens. Initially, polyps are benign but do become cancerous over time. This type of colorectal cancer is rare. It only occurs in 1% of all colon cancer cases. The likelihood of colon cancer is almost 100% by age 40. Many opt to have most or all of their colon removed as a preventive measure.


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  • Colorectal cancer. American Cancer Society website. Available at: http://www.cancer.org/acs/groups/cid/documents/webcontent/003096-pdf.pdf. Accessed February 27, 2020.
  • Colorectal cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/colorectal-cancer. Updated January 22, 2020. Accessed February 27, 2020.
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  • Mohei Abouzied, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.