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Extending the Interval to Repeat Colonoscopy After Negative Findings for Colorectal Cancer on Index Colonoscopy
abstract
This abstract is available on the publisher's site.
Access this abstract nowIMPORTANCE
For individuals without a family history of colorectal cancer (CRC), colonoscopy screening every 10 years is recommended to reduce CRC incidence and mortality. However, debate exists about whether and for how long this 10-year interval could be safely expanded.
OBJECTIVE
To assess how many years after a first colonoscopy with findings negative for CRC a second colonoscopy can be performed.
DESIGN, SETTING, AND PARTICIPANTS
This cohort study leveraged Swedish nationwide register-based data to examine CRC diagnoses and CRC-specific mortality among individuals without a family history of CRC. The exposed group included individuals who had a first colonoscopy with findings negative for CRC at age 45 to 69 years between 1990 and 2016. The control group included individuals matched by sex, birth year, and baseline age (ie, the age of their matched exposed individual when the exposed individual's first colonoscopy with findings negative for CRC was performed). Individuals in the control group either did not have a colonoscopy during the follow-up or underwent colonoscopy that resulted in a CRC diagnosis. Up to 18 controls were matched with each exposed individual. Individuals were followed up from 1990 to 2018, and data were analyzed from November 2022 to November 2023.
EXPOSURE
A first colonoscopy with findings negative for CRC, defined as a first colonoscopy without a diagnosis of colorectal polyp, adenoma, carcinoma in situ, or CRC before or within 6 months after screening.
MAIN OUTCOMES AND MEASURES
The primary outcomes were CRC diagnosis and CRC-specific death. The 10-year standardized incidence ratio and standardized mortality ratio were calculated to compare risks of CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals.
RESULTS
The sample included 110 074 individuals (65 147 females [59.2%]) in the exposed group and 1 981 332 (1 172 646 females [59.2%]) in the control group. The median (IQR) age for individuals in both groups was 59 (52-64) years. During up to 29 years of follow-up of individuals with a first colonoscopy with findings negative for CRC, 484 incident CRCs and 112 CRC-specific deaths occurred. After a first colonoscopy with findings negative for CRC, the risks of CRC and CRC-specific death in the exposed group were significantly lower than those in their matched controls for 15 years. At 15 years after a first colonoscopy with findings negative for CRC, the 10-year standardized incidence ratio was 0.72 (95% CI, 0.54-0.94) and the 10-year standardized mortality ratio was 0.55 (95% CI, 0.29-0.94). In other words, the 10-year cumulative risk of CRC in year 15 in the exposed group was 72% that of the 10-year cumulative risk of CRC in the control group. Extending the colonoscopy screening interval from 10 to 15 years in individuals with a first colonoscopy with findings negative for CRC could miss the early detection of only 2 CRC cases and the prevention of 1 CRC-specific death per 1000 individuals, while potentially avoiding 1000 colonoscopies.
CONCLUSIONS AND RELEVANCE
This cohort study found that for the population without a family history of CRC, the 10-year interval between colonoscopy screenings for individuals with a first colonoscopy with findings negative for CRC could potentially be extended to 15 years. A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.
Additional Info
Disclosure statements are available on the authors' profiles:
Longer Interval Between First Colonoscopy With Negative Findings for Colorectal Cancer and Repeat Colonoscopy
JAMA Oncol 2024 May 02;[EPub Ahead of Print], Q Liang, T Mukama, K Sundquist, J Sundquist, H Brenner, E Kharazmi, M FallahFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Since 2019, a flurry of large observational studies has shown a low or very low risk for incident colorectal cancer (CRC) and CRC mortality after a negative result on colonoscopy, suggesting that the interval for screening colonoscopy for average-risk (defined as having no high-risk personal or family history of CRC) adults aged 50–75 years could be extended beyond 10 years. The original recommendation for the 10-year interval was based on indirect data from a limited understanding of the dwell time for adenomas along with expert gestalt.
These new data from Sweden are perhaps the strongest evidence for a longer (specifically, 15-year) interval for rescreening colonoscopy as they include follow-up beyond 10 years in 28,586 persons exposed to colonoscopy and 563,189 unexposed controls. In addition to using several national datasets to assemble and analyze a nationwide representative “sample," the investigators used 10-year standardized incidence ratios (SIRs) and 10-year standardized mortality ratios at different time points in addition to the conventional annual SIRs and standardized mortality ratios. The 10-year cumulative CRC risk in year 15 in the group with negative results on colonoscopy was 72% (CI, 54%–94%) of that in the control group, and the yearly SIRs from years 1 through 14 were all statistically significantly lower than 1. Results of sensitivity analyses that considered sex, age at first colonoscopy with negative findings, and calendar time, with adjustment for specific covariates (eg, obesity, alcohol use disorder, others) supported the primary results.
This study, along with several other population-based observational studies from different countries with different study designs, supports a longer rescreening interval following a negative result on colonoscopy in average-risk persons. The quality of these direct data is more robust than the indirect data that were used to lower the age at which to begin CRC screening. If the of age 45 years is the new 50 for starting CRC screening, then 15 (years) should be the new (10-year) interval for rescreening average-risk persons with a negative result on index colonoscopy. Fine-tuning of this new interval may be possible with consideration of patient age, perhaps sex, and quality metrics of the endoscopist.