Family History

Your Family History — It Matters!

If one or more of your family member(s) had colorectal cancer or a pre-cancerous colorectal polyp(s) called an adenoma, you could be at increased risk. This means that your chance of developing the disease is increased and may require screening earlier, and/or more often, than those at average-risk.

About 1 in 3 people, who are diagnosed with colorectal cancer, have at least one family member diagnosed with colorectal cancer or with pre-cancerous (adenomatous) colorectal polyp(s).

Not having a family history does not protect you against developing colorectal cancer. In fact, most colorectal cancers are found in people without a family history of the disease.

Talking about Family History

Understanding your family’s medical and cancer history is very important, as it may help you and your doctor determine your risk of developing certain types of cancers. We encourage you to talk with your family about their health and medical history.

Indicators for Increased Risk:

  • One parent, brother, or sister with colorectal cancer
  • Two grandparents, aunts, or uncles with colorectal cancer at any age
  • Parent, brother, or sister with a pre-cancerous polyp(s).
  • Two grandparents, aunts, or uncles with a pre-cancerous polyp(s).
  • Personal history of adenoma, certain serrated polyps or colorectal cancer

Indicators for High and Highest Risk:

  • Three or more relatives with similar or related cancers listed below:
    • colon
    • rectal
    • endometrial
    • gastric
    • small bowel
    • ovarian
    • urinary system
    • renal pelvis
    • pancreatic
    • brain (usually glioblastoma)
    • sebaceous skin lesions
    • keratocanthomas

  • Two generations of family members with colorectal cancer (see examples below)
    • mother and her father
    • father and his mother
    • parent and their brother or sister (aunts or uncle)

  • One or more relative(s) under the age of 50 diagnosed with colorectal cancer or with a test finding more than 10 pre-cancerous polyps

  • Suspected or confirmed hereditary cancer syndrome such as Familial Adenomatous Polyposis (FAP) or Hereditary Nonpolyposis Colorectal Cancer (HNPCC), often called Lynch syndrome.

It is important to talk to your family about their medical and cancer history, as it may help you and your doctor determine your risk of developing certain types of cancers.

Visit the American Cancer Society and the Centers for Disease Control and Prevention for more information on family history and how it can impact your colorectal cancer risk.