Is a family history of colorectal cancer a risk factor for developing it?

Colorectal cancer can occur for a variety of reasons, but some people have a higher risk because they have inherited a genetic susceptibility to it. In such families, a faulty gene associated with cancer is passed down from one generation to the next.

There may be an inherited tendency to develop any gastrointestinal cancer, including colorectal cancer, if:

  • You have a parent, brother, sister, or child who has been diagnosed with a gastrointestinal cancer or uterine cancer.
  • You or any family member have had a gastrointestinal cancer or uterine cancer before the age of 50.
  • You or a relative have had more than one cancer (including colorectal cancer).
  • You or a relative have had pre-cancerous conditions such as polyps in the colon or stomach.
  • You have a known history of a hereditary colon cancer syndrome, such as:
    • hereditary non-polyposis colon cancer (HNPCC)
    • familial adenomatous polyposis (FAP)
    • juvenile polyposis
    • Gardner syndrome
    Carrie Bilicki
    Oncology Nursing

    Colorectal cancer is the third leading cause of cancer in both men and women. By age 70, the risk of colorectal cancer is 3-5% in the general population. The risk of cancer increases when there is a family history of colon cancer present. Having one first-degree relative (parent, sibling, or child) increases the risk about twofold over that of the general population.

    Additionally, approximately 10% of colorectal cancers are due to an inherited cancer predisposition syndrome which places individuals at significantly increased risk of the development of colorectal cancer along with other cancer. By identifying at-risk family members, medical management recommendations could be made to reduce and possibly prevent colorectal cancer.

    Yes. Most colorectal cancers occur in people without a family history of colorectal cancer. Still, as many as 1 in 5 people who develop colorectal cancer have other family members who have been affected by this disease.
    People with a history of colorectal cancer or adenomatous polyps in one or more first-degree relatives (parents, siblings, or children) are at increased risk. The risk is about doubled in those with a single affected first-degree relative. It is even higher if the first-degree relative is diagnosed at a young age, or if more than one first-degree relative is affected.
    The reasons for the increased risk are not clear in all cases. Cancers can "run in the family" because of inherited genes, shared environmental factors, or some combination of these.
    If you have a family history of adenomatous polyps or colorectal cancer, you should talk with your doctor about the possible need to begin screening before age 50. If you have had adenomatous polyps or colorectal cancer, it's important to tell your close relatives so that they can pass along that information to their doctors and start screening at the right age.

    Yes, a family history of colorectal cancer is a risk factor for developing the disease. People who have a close relative (parent or sibling) with colon cancer are at greater risk than those who do not. If this is the case, we recommend that you get a colonoscopy 10 years before the age that your family member developed the cancer.

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    Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.