From the Guidelines
Colonoscopy Initiation and Termination
Colonoscopy should start at age 45 for individuals with average risk of colorectal cancer and stop at age 75 1. However, for individuals with a family history of colorectal cancer or other high-risk factors, colonoscopy may start earlier, at age 40 or even younger, and continue beyond age 75 on a case-by-case basis 1.
Key Considerations for Initiation
- Family History: Individuals with a first-degree relative with colorectal cancer at age <60 years or 2 first-degree relatives with these findings at any age should undergo screening by colonoscopy every 5 years, beginning 10 years before the age at diagnosis of the youngest affected relative, or at age 40, whichever is earlier 1.
- Average Risk: Average-risk adults in good health with a life expectancy of more than 10 years should begin screening at age 45 years with any test (qualified recommendation) and screen adults between ages 50 and 75 years with any test (strong recommendation) 1.
Key Considerations for Termination
- Age and Life Expectancy: Screening should be stopped if the patient has a significant comorbidity that makes the procedure risky, or if the patient's life expectancy is less than 5-10 years 1.
- Previous Screening Results: It's also recommended to stop colonoscopy if the patient has had a normal colonoscopy result in the past 10 years and has no new symptoms or high-risk factors 1.
- Individualized Decision: The decision to start or stop colonoscopy should be individualized and based on a thorough discussion between the patient and their healthcare provider, considering prior screening history, life expectancy, CRC risk, and patient preferences 1.
High-Risk Factors
- Family History of Advanced Adenoma: Individuals with a family history of advanced adenoma may confer the same risk as first-degree relatives with colorectal cancer, and any adenoma < age 40 years may confer a similar risk to colorectal cancer < age 50 years 1.
- Inherited Colorectal Syndromes: If a patient meets the criteria for an inherited colorectal syndrome, specific guidelines for further risk evaluation and management should be followed 1.
From the Research
Initiation of Colonoscopy
- The American College of Physicians recommends starting screening for colorectal cancer in asymptomatic average-risk adults at age 50 years 2.
- However, some studies suggest that screening should begin at age 45 for average-risk individuals 3, 4.
- For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40 3.
- A study found that older age at first screening colonoscopy is associated with an increased risk of colorectal adenomas and cancer, highlighting the need for guideline adherence 5.
Termination of Colonoscopy
- The American College of Physicians recommends stopping screening for colorectal cancer in asymptomatic average-risk adults older than 75 years or in asymptomatic average-risk adults with a life expectancy of 10 years or less 2.
- However, a cohort study found that screening endoscopy after 75 years of age was associated with reduced risk of CRC incidence and CRC-related mortality, regardless of screening history 6.
- The study suggests that screening endoscopy after 75 years of age may be beneficial for individuals without significant comorbidities 6.
Screening Intervals
- The recommended screening intervals for colonoscopy are every 10 years for average-risk individuals and every 5-10 years for high-risk individuals 3.
- The American College of Physicians recommends selecting a screening test for colorectal cancer in consultation with the patient, based on a discussion of benefits, harms, costs, availability, frequency, and patient values and preferences 2.