Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance

Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous histology or high-grade dysplasia, or colorectal cancer [CRC]) and assessed whether baseline colonoscopy findings were associated with long-term outcomes. We collected data from the Department of Veterans Affairs Cooperative Studies Program Study on 3121 asymptomatic veterans (50–75 years old) who underwent a screening colonoscopy from 1994 through 1997 at 13 medical centers and were then followed for 10 years or until death. We included 1915 subjects with at least 1 surveillance colonoscopy and estimated cumulative incidence of advanced neoplasia by Kaplan-Meier curves. We then fit a longitudinal joint model to estimate risk of advanced neoplasia at each subsequent examination after baseline, adjusting for multiple colonoscopies within individuals. Through 10 years of follow-up, there were 146 individuals among all baseline colonoscopy groups found to have at least 1 incident advanced neoplasia. The cumulative 10-year incidence of advanced neoplasia was highest among those with baseline CRC (43.7%; 95% CI 13.0%–74.4%), followed by those with baseline advanced adenoma (AA) (21.9%; 95% CI 15.7–28.1). The cumulative 10-year incidence of advanced neoplasia was 6.3% (95% CI 4.1%–8.5%) and 4.1% (95% CI 2.7%–5.4%) for baseline 1 to 2 small adenomas (