From the Guidelines
Patients with average risk of colon cancer should begin colonoscopy screening at age 45. This recommendation is based on the most recent guidelines from the American Cancer Society, 2018, and the National Comprehensive Cancer Network, 2022, as well as the US Multi-Society Task Force on Colorectal Cancer, 2022, which all suggest starting screening at age 45 for average-risk adults 1. The earlier screening age was adopted because colorectal cancer rates have been increasing in younger adults.
Key Points to Consider
- Colonoscopy screening should then continue every 10 years until age 75 for those with normal results.
- Between ages 76-85, the decision to screen should be individualized based on overall health, prior screening history, and life expectancy.
- After age 85, routine screening is generally not recommended.
- Alternative screening methods include stool-based tests (FIT annually or multi-target stool DNA every 1-3 years) or CT colonography every 5 years, though colonoscopy remains the gold standard as it allows for both detection and removal of precancerous polyps in a single procedure. Some key considerations for patients preparing for colonoscopy include:
- Following a clear liquid diet the day before
- Completing a bowel preparation regimen as prescribed by their doctor to ensure adequate visualization of the colon As noted in the guidelines, the recommendation to start screening at age 45 is based on a qualified recommendation from the American Cancer Society and a weak recommendation from the USMSTF, but a strong recommendation from the National Comprehensive Cancer Network 1.
From the Research
Colonoscopy Screening Guidelines
- The American College of Gastroenterology recommends that average-risk patients undergo a screening colonoscopy at age 50 2.
- However, some studies suggest that screening may be beneficial for individuals between 45 and 75 years of age 3.
- For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40 3.
Age to Start Colonoscopy Screening
- A study published in 2003 found that asymptomatic 50- to 59-year-olds with negative fecal occult blood tests and negative family histories had a 58% incidence of neoplastic polyps, supporting the recommendation to start screening at age 50 2.
- Another study published in 2024 recommended screening between 45 and 75 years for average-risk individuals, with more frequent screening for high-risk individuals 3.
- A 2008 study compared the prevalence of colorectal neoplasia in asymptomatic average-risk individuals ages 40-49 years and 50-59 years, finding similar prevalence of total adenomas but higher prevalence of advanced neoplasia in the 50-59 years age group 4.
Considerations for Older Adults
- Screening and ongoing surveillance should be considered in patients who have a life expectancy of 10 years or more 5.
- The decision to initiate or discontinue screening for CRC in older patients should be based on a case-by-case individualized discussion, taking into account the patient's morbidity and mortality risk from CRC, underlying comorbidities, functional status, and preferences for screening 5.
- A 2010 review addressed the benefits and harms of screening in the elderly, emphasizing the importance of physician emphasis on health status, life expectancy, and patient preferences in decision-making regarding colon cancer screening 6.