What are the criteria for identifying high-risk patients for colon cancer screening?

From the Guidelines

High-risk patients for colon cancer should begin screening earlier and undergo more frequent surveillance than average-risk individuals, with specific criteria including a family history of colorectal cancer, advanced adenomas in first-degree relatives, or hereditary syndromes like Lynch syndrome. Patients with a family history of colorectal cancer or advanced adenomas in first-degree relatives should start screening at age 40 or 10 years before the youngest affected relative's diagnosis, whichever comes first, as recommended by the U.S. Multi-Society Task Force on Colorectal Cancer 1.

Key Criteria for High-Risk Patients

• A family history of colorectal cancer, with the greatest relative risk appearing in persons <50 years who have a first-degree relative with CRC diagnosed at <50 years 1
• Advanced adenomas in first-degree relatives, with documentation of an advanced adenoma or a report of a polyp requiring surgical resection 1
• Hereditary syndromes like Lynch syndrome, which requires colonoscopy every 3-5 years beginning 10 years before the age at diagnosis of the youngest affected relative 1

Screening Recommendations

• Patients with Lynch syndrome should begin colonoscopy screening at an earlier age, with intervals of every 3-5 years 1
• Those with a single first-degree relative with colorectal cancer should begin screening at age 40, with options for screening and recommended intervals similar to those for average-risk persons 1
• Individuals with a family history of adenomas in a first-degree relative should not undergo early more-frequent screening unless there is clear documentation of an advanced adenoma in a first-degree relative 1

Importance of Early Screening

Early screening is crucial for high-risk patients, as it can help detect colorectal cancer at an early stage, when it is more treatable 1. Compliance in young persons with a family history of CRC is suboptimal, and clinicians should make special efforts to ensure that screening occurs 1.

From the Research

Criteria for Identifying High-Risk Patients

The criteria for identifying high-risk patients for colon cancer screening include:

• A personal or family history of advanced adenomas or colorectal cancer 2
• A personal history of inflammatory bowel disease 2
• Genetic polyposis syndromes 2
• Familial clustering of colorectal cancers, with the magnitude of the risk depending on the age at diagnosis of the index case, the degree of kinship of the index case to the at-risk case, and the number of affected relatives 3

Family History and Risk

• Individuals with a first-degree relative with colon cancer have a twofold to threefold increased risk of the disease 3
• The risk increases with the number of affected relatives and the degree of kinship 3
• Individuals with two first-degree relatives affected with colon cancer or one first-degree relative diagnosed under the age of 60 years should have colonoscopy beginning at age 40, or 10 years younger than the earliest case in the family 3, 2

Screening Recommendations

• Average risk colon cancer screening is recommended for individuals with a first-degree relative with colon cancer, starting at age 40 years 3
• Colonoscopy should be repeated every five years if negative 3
• Individuals with a stronger family history of colon cancer syndromes should consider the possibility of one of the inherited syndromes 3
• Screening colonoscopy should begin at 40 years of age or 10 years younger than the earliest diagnosis in the family for individuals with a first-degree relative with colorectal cancer or advanced adenoma diagnosed before 60 years of age or two first-degree relatives diagnosed at any age 2

Special Considerations

• Individuals with ulcerative colitis or Crohn disease with colonic involvement should undergo colonoscopy starting eight to 10 years after the onset of symptoms and repeat every one to three years 2
• Individuals with hereditary nonpolyposis colorectal cancer should begin colonoscopy at 25 years of age and repeat every one to two years 2
• Individuals with adenomatous polyposis syndromes should begin screening at 10 years of age or in their mid-20s, depending on the syndrome, and repeat colonoscopy every one to two years 2