CRC rescreening interval may be extended beyond 10 years for low-risk individuals, study suggests
Individuals with negative colonoscopy screening results had a persistently lower risk of colorectal cancer (CRC) incidence and mortality for at least 20 years compared with individuals whose results showed CRC or polyps, according to a cohort study.
The rescreening interval following a negative colonoscopy screening (NCS) may be extended beyond the currently recommended 10 years, especially among adults with low-risk profiles, results of a cohort study suggest.
Researchers assessed data from 195,453 individuals (median age at baseline, 44 years; 81% female) to determine long-term colorectal cancer (CRC) incidence and mortality after NCS results (no presence of CRC or polyps) and according to a risk score based on major demographic and lifestyle risk factors, including age and sex. All individuals were participants in the Nurses' Health Study, Nurses' Health Study II, and Health Professionals Follow-up Study and were followed from 1988 and 1991 to 2020 (median follow-up, 12 years). Data from the National Health and Nutrition Examination Survey (NHANES) from January 2017 to December 2018 were used to compare CRC risk with that of the general U.S. population. Findings were published by JAMA Oncology on Nov. 27.
Of 81,151 individuals with NCS results and 114,302 with no screening, 394 and 2,229 CRC cases and 167 and 637 CRC deaths were documented, respectively. Negative screenings were associated with lower CRC incidence (hazard ratio [HR], 0.51; 95% CI, 0.44 to 0.58) and mortality (HR, 0.56; 95% CI, 0.46 to 0.70) for 20 years. Individuals with negative results who were at intermediate risk (scores, 6 to 7) and low risk (scores, 0 to 5) did not reach the 10-year cumulative incidence of CRC (0.78%) seen among high-risk individuals (scores, 8 to 12) until 16 and 25 years after the initial screening, respectively. CRC incidence was lower for distal colon cancer (HR, 0.34; 95% CI, 0.35 to 0.46) and rectal cancer (HR, 0.41; 95% CI, 0.30 to 056) than for proximal colon cancer (HR, 0.68 [95% CI, 0.56 to 0.84]; P<0.001 for heterogeneity). In addition, when a 10-year risk estimate of 0.61% for individuals 50 years of age was used (based on data from the Surveillance, Epidemiology, and End Results Program), high-risk individuals reached this level at approximately seven years versus 13 and 20 years for those at intermediate and low risk, respectively.
Limitations to the study include a lack of information on colonoscopy quality and the potential for residual confounding.
“Individuals with NCS results may consider, through discussion with physicians, extending their surveillance interval beyond the currently recommended 10 years, particularly for those who have a low-risk profile based on known CRC risk factors,” the authors concluded.