At what age should a 38-year-old woman with no medical history or family history of cancer start screening for colon cancer?

Colorectal Cancer Screening for a 38-Year-Old Average-Risk Woman

This 38-year-old woman with no personal or family history of cancer should begin colorectal cancer screening at age 45 years. 1, 2

Recommended Screening Age

• Average-risk adults should initiate screening at age 45 years, which represents the current standard recommendation from the American Cancer Society (qualified recommendation) and the US Preventive Services Task Force (Grade B recommendation). 1, 2

• The recommendation to begin at age 45 is based on rising colorectal cancer incidence in younger birth cohorts, with early-onset colorectal cancer now accounting for an estimated 10.5% of new cases. 1

• The stronger evidence supports screening beginning at age 50 years (Grade A recommendation from USPSTF, strong recommendation from ACS), but the age 45 threshold reflects the concerning epidemiologic trend of increasing incidence in adults under 50. 1

Why Not Earlier for This Patient

• This patient has no high-risk features that would warrant earlier screening:

  • No first-degree relative with colorectal cancer or advanced adenoma diagnosed before age 60 1, 2
  • No personal history of inflammatory bowel disease 1, 2
  • No known hereditary cancer syndrome 1

• Screening at age 40 is reserved for individuals with a first-degree relative diagnosed with colorectal cancer or advanced adenoma before age 60, or those with two or more first-degree relatives affected at any age. 1, 2, 3

Screening Options When She Reaches Age 45

First-tier screening options include: 3

• Colonoscopy every 10 years 1, 2, 3
• Annual fecal immunochemical test (FIT) 1, 2, 3

Second-tier acceptable alternatives include: 1, 3

• CT colonography every 5 years 1
• Multitarget stool DNA test (sDNA-FIT) every 3 years 1
• Flexible sigmoidoscopy every 5 years 1

Duration of Screening

• Continue screening through age 75 years if in good health with life expectancy greater than 10 years. 1, 2

• Between ages 76-85, individualize decisions based on prior screening history, health status, and life expectancy. 1

• Discontinue screening after age 85 years, as harms outweigh benefits. 1, 2

Common Pitfalls to Avoid

• Do not screen this 38-year-old patient now unless she develops symptoms or new risk factors emerge (such as a family member being diagnosed with colorectal cancer). 1

• Verify family history carefully at age 45 before initiating average-risk screening, as family history information is often incomplete or inaccurate and could change the screening approach. 1, 2

• If a first-degree relative is subsequently diagnosed with colorectal cancer or advanced adenoma before age 60, she would need to begin screening at age 40 or 10 years before the age of diagnosis of the affected relative, whichever comes first. 1, 2, 3