Longer Interval Between First Colonoscopy With Negative Findings for Colorectal Cancer and Repeat Colonoscopy

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Current guidelines recommend colonoscopy every 10 years for colorectal cancer (CRC) screening in average-risk individuals.
• Debate exists regarding the optimal screening interval and the potential for safely extending it.

Purpose of the Study:

• To evaluate the safety and efficacy of extending the colonoscopy screening interval beyond 10 years for individuals with negative findings on their first colonoscopy.

Main Methods:

• A nationwide Swedish cohort study analyzed data from individuals aged 45-69 who had a first colonoscopy with negative findings between 1990-2016.
• Matched control groups were established, and CRC diagnoses and CRC-specific mortality were compared over up to 29 years of follow-up.

Main Results:

• Individuals with a negative first colonoscopy showed significantly lower risks of CRC and CRC-specific death for up to 15 years compared to controls.
• Extending the interval to 15 years was associated with a 10-year standardized incidence ratio of 0.72 and a standardized mortality ratio of 0.55.
• Extending the interval to 15 years could miss 2 CRC cases and prevent 1 CRC death per 1000 individuals, while avoiding 1000 colonoscopies.

Conclusions:

• The 10-year colonoscopy screening interval may be safely extended to 15 years for individuals without a family history of CRC and negative initial findings.
• Longer screening intervals could reduce the number of unnecessary invasive procedures.