Negative Colonoscopy? 15-Year Screening Interval May Be Safe

TOPLINE:

The recommended 10-year interval between screening colonoscopies may be safely extended to 15 years in adults with no family history of colorectal cancer (CRC) whose first colonoscopy is negative for CRC, a population-based study suggests.

METHODOLOGY:

• Using Swedish nationwide registry data, researchers compared 110,074 individuals who had a first colonoscopy with negative findings for CRC at age 45-69 years (exposed group) with more than 1.9 million matched controls who either did not have a colonoscopy during the study period or underwent colonoscopy that led to a CRC diagnosis.
• They calculated 10-year standardized incidence ratio (SIR) and standardized mortality ratio (SMR) to compare risks for CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals.

TAKEAWAY:

• During up to 29 years of follow-up, 484 incident CRCs and 112 CRC deaths occurred in the group with a negative initial colonoscopy.
• Up to 15 years after negative colonoscopy, the 10-year cumulative risk for CRC and CRC mortality was lower than in the control group, with an SIR of 0.72 and SMR of 0.55, respectively.
• Extending the screening interval from 10 to 15 years would miss early detection of only two CRC cases and prevention of only one CRC death per 1000 individuals, while potentially avoiding 1000 colonoscopies.

IN PRACTICE:

“This study provides evidence for recommending a longer colonoscopy screening interval than what is currently recommended in most guidelines for populations with no familial risk of CRC,” the authors wrote. “A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.”

SOURCE:

The study, with first author Qunfeng Liang, MSc, with the German Cancer Research Center, Heidelberg, Germany, was published online on May 2 in JAMA Oncology.

LIMITATIONS:

The study population primarily included White individuals, particularly ethnic Swedish individuals, so external validation would be necessary to generalize the recommendation to other populations. The researchers lacked data on non-endoscopic tests, such as fecal occult blood tests, which could have been performed as a substitution for colonoscopy during the interval between colonoscopy screenings.

DISCLOSURES:

The study had no specific funding. The authors had no relevant conflicts of interest.

A version of this article appeared on Medscape.com.