What are the screening and prevention recommendations for someone with a family history of colon cancer?

Colorectal Cancer Screening Recommendations for Individuals with Family History

For individuals with a family history of colorectal cancer, screening should begin at age 40 or 10 years before the age of diagnosis of the youngest affected relative, whichever comes first, with colonoscopy as the preferred screening method. 1

Risk Stratification Based on Family History

One First-Degree Relative with CRC Diagnosed at Age ≥60 Years

• Begin screening at age 40 years 1
• Use the same screening tests and intervals as average-risk individuals: colonoscopy every 10 years or annual FIT 1
• If colonoscopy is declined, annual FIT is strongly recommended as an alternative 1

One First-Degree Relative with CRC Diagnosed at Age <60 Years

• Begin colonoscopy at age 40 years or 10 years before the age of diagnosis of the affected relative, whichever comes first 1
• Repeat colonoscopy every 5 years 1
• If colonoscopy is declined, annual FIT is recommended 1

Two or More First-Degree Relatives with CRC at Any Age

• Begin colonoscopy at age 40 years or 10 years before the age of diagnosis of the youngest affected relative, whichever comes first 1
• Repeat colonoscopy every 5 years 1
• The risk is approximately 3-4 times higher than the general population 1

First-Degree Relative with Advanced Adenoma

• An advanced adenoma is defined as an adenoma ≥10 mm in size, with high-grade dysplasia, or villous features 1
• Screen as you would for a first-degree relative with CRC 1
• Documentation of the advanced nature of the adenoma is important; without clear documentation, assume the adenoma was not advanced 1

First-Degree Relative with Advanced Serrated Lesion

• An advanced serrated lesion is defined as a sessile serrated polyp (SSP) ≥10 mm in size, an SSP with cytologic dysplasia, or a traditional serrated adenoma ≥10 mm in size 1
• Screen similar to first-degree relatives with advanced adenomas 1

Second-Degree or Third-Degree Relatives Only

• Follow average-risk screening guidelines 1
• Second-degree relatives with CRC increase risk by approximately 1.5-fold 1

Special Considerations

Family Colon Cancer Syndrome X

• Families that meet clinical criteria for hereditary nonpolyposis CRC but have microsatellite-stable CRCs 1
• Colonoscopy every 5 years beginning 10 years before the age of diagnosis of the youngest affected relative or age 40, whichever is earlier 1

Lynch Syndrome

• Colonoscopy every 3-5 years beginning 10 years before the age of diagnosis of the youngest affected relative 1
• Consider genetic counseling and testing 1

Age Considerations

• The greatest relative risk appears to be in persons <50 years who have a first-degree relative with CRC diagnosed at <50 years 1
• If a person with a single first-degree relative with CRC reaches approximately age 60 without significant colorectal neoplasia, the interval between examinations may be expanded 1

Prevention Strategies Beyond Screening

• Annual FIT should be offered to those who decline colonoscopy 1
• Compliance in young persons with a family history of CRC is suboptimal; special efforts should be made to ensure screening occurs 1
• Quality indicators for colonoscopy are important for effective screening, including cecal intubation rates, withdrawal time, and adenoma detection rates 1

Common Pitfalls and Caveats

• Family history information is often incomplete or inaccurate; attempt to verify the diagnosis and age of onset in affected relatives when possible 1
• Without clear documentation of advanced adenomas in relatives, assume adenomas were not advanced 1
• The risk of CRC increases with the number of affected relatives and younger age of diagnosis in relatives 1
• Screening recommendations for individuals with family history are considered provisional as mortality reduction studies specifically for this population are limited 1