Study shows extending interval between colonoscopies feasible after negative result

For individuals without a family history of colorectal cancer (CRC), increasing the interval between colonoscopies for those with a first colonoscopy with negative findings seems safe and can avoid unnecessary colonoscopies, according to a study published online May 2 in JAMA Oncology.

Qunfeng Liang, from the German Cancer Research Center in Heidelberg, and colleagues assessed how many years after a first colonoscopy with findings negative for CRC a second colonoscopy can be performed.

The exposed group included individuals without a family history of CRC who had a first colonoscopy with findings negative for CRC at age 45 to 69 years between 1990 and 2016, while the control group included matched individuals who did not have a colonoscopy during follow-up or who underwent colonoscopy resulting in CRC diagnosis (110,074 and 1,981,332 individuals, respectively).

The researchers found that 484 incident CRCs and 112 CRC-specific deaths occurred during up to 29 years of follow-up of individuals with a first colonoscopy with findings negative for CRC.

For 15 years, the risks for CRC and CRC-specific death were significantly lower in the exposed group than in matched controls. The 10-year standardized incidence ratio was 0.72 at 15 years after a first colonoscopy with negative findings, and the 10-year standardized mortality ratio was 0.55.

Extending the colonoscopy screening interval from 10 to 15 years could miss the early detection of two CRC cases and prevention of one CRC-specific death per 1,000 individuals and could potentially avert 1,000 colonoscopies.

“A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations,” the authors write.