In a Swedish cohort study reported in JAMA Oncology, Liang et al found that among individuals with no family history of colorectal cancer and a negative first screening colonoscopy, the interval to repeat colonoscopy could be extended beyond the currently recommended 10 years.

Study Details  

The study used Swedish nationwide register-based data to examine colorectal cancer diagnoses and colorectal cancer–specific mortality among individuals without a family history of colorectal cancer. Individuals with findings on first colonoscopy negative for colorectal cancer (no diagnosis of polyps, adenomas, carcinoma in situ, or colorectal cancer) at age 45 to 69 between 1990 and 2016 (exposed group) were compared with up to 18 control individuals (control group) matched for sex, birth year, and baseline age; individuals in the control group either did not have a colonoscopy during follow-up or underwent a colonoscopy that resulted in a colorectal cancer diagnosis. Study participants were followed through 2018.

Key Findings

The study population included 110,074 individuals in the exposed group and 1,981,332 in the control group. With up to 29 years of follow-up for individuals in the exposed group, 484 incident colorectal cancer cases and 112 colorectal cancer–specific deaths occurred.

At 15 years after negative first colonoscopy in the exposed group, the 10-year standardized incidence ratio was 0.72 (95% confidence interval [CI] = 0.54–0.94), and the 10-year standardized colorectal cancer–specific mortality ratio was 0.55 (95% CI = 0.29–0.94). Thus, the 10-year cumulative risks of colorectal cancer and colorectal cancer–specific mortality at 15 years in the exposed group were equivalent to 72% and 55% of the 10-year cumulative risks in the control group, respectively.

It was estimated that extending the colonoscopy screening interval from 10 to 15 years in individuals with a negative first colonoscopy may result in failure to detect two colorectal cancer cases and failure to prevent one colorectal cancer–specific death per 1,000 individuals while avoiding 1,000 colonoscopies.

The investigators concluded: “This cohort study found that for the population without a family history of colorectal cancer, the 10-year interval between colonoscopy screenings for individuals with a first colonoscopy with findings negative for colorectal cancer could potentially be extended to 15 years. A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.”

Mahdi Fallah, MD, PhD, of the Division of Preventive Oncology, National Center for Tumor Diseases, German Cancer Research Center, Heidelberg, Germany, is the corresponding author of the JAMA Oncology article.

Disclosure: For full disclosures of the study authors, visit jamanetwork.com.