What are the current guidelines for colon cancer screening, including the recommended age to start screening?

Current Guidelines for Colorectal Cancer Screening

The American Cancer Society and multiple professional organizations now recommend starting colorectal cancer screening at age 45 for average-risk individuals, with screening continuing until age 75 for those in good health with a life expectancy of more than 10 years. 1, 2

Starting Age for Screening

• Average-risk individuals: Begin screening at age 45 1, 2

  • This is a qualified recommendation from the American Cancer Society (ACS) based on increasing CRC incidence in younger adults and modeling studies
  • The recommendation for screening at age 50+ remains a strong recommendation

• Increased-risk individuals: Begin screening earlier 1

  • Family history of CRC or advanced adenoma in a first-degree relative (FDR) diagnosed before age 60: Begin at age 40 or 10 years before the age of diagnosis of the youngest affected relative, whichever is earlier
  • Family history of CRC in 2 or more FDRs at any age: Begin at age 40 or 10 years before earliest diagnosis, whichever is earlier

Recommended Screening Options

Stool-based tests:

• Fecal immunochemical test (FIT) annually
• High-sensitivity guaiac-based fecal occult blood test annually
• Multitarget stool DNA test every 3 years

Structural (visual) examinations:

• Colonoscopy every 10 years
• CT colonography every 5 years
• Flexible sigmoidoscopy every 5 years

When to Stop Screening

• Age 75: Consider stopping screening in adults with negative prior screening tests who are up to date with screening (qualified recommendation) 1, 2
• Age 76-85: Individualize screening decisions based on:
  • Prior screening history
  • Overall health status
  • Life expectancy (continue if >10 years)
  • Patient preferences
• Age >85: Discourage continued screening (qualified recommendation) 1, 2

Screening Test Selection Algorithm

1. First-tier options (preferred screening methods):

   • Colonoscopy every 10 years
   • Annual FIT

2. Second-tier options:

   • CT colonography every 5 years
   • FIT-fecal DNA test every 3 years
   • Flexible sigmoidoscopy every 5-10 years

3. Third-tier option:

   • Capsule colonoscopy every 5 years (limited evidence)

Special Considerations

• Rising CRC incidence in younger adults: The recommendation to begin screening at age 45 is based on evidence showing increasing CRC incidence in adults under 50, with a strong birth-cohort effect 1

• Follow-up of positive tests: All positive results on non-colonoscopy screening tests must be followed up with timely colonoscopy 1

• Test selection factors: Consider patient preference, test availability, and individual risk factors when selecting the appropriate screening method

• Common pitfalls to avoid:

  • Failing to follow up positive stool-based tests with colonoscopy
  • Neglecting to consider family history when determining screening start age
  • Continuing screening in very elderly patients (>85) or those with limited life expectancy
  • Not recognizing symptoms that warrant diagnostic evaluation regardless of screening status

The shift to beginning screening at age 45 represents a significant change in practice based on the observed increase in early-onset colorectal cancer. While the evidence for screening at age 50+ remains stronger, the qualified recommendation to begin at 45 acknowledges the changing epidemiology of colorectal cancer in younger populations.