Advanced neoplasia in Veterans at screening colonoscopy using the National Cancer Institute Risk Assessment Tool

Abstract

BackgroundAdapting screening strategy to colorectal cancer (CRC) risk may improve efficiency for all stakeholders however limited tools for such risk stratification exist. Colorectal cancers usually evolve from advanced neoplasms that are present for years. We applied the National Cancer Institute (NCI) CRC Risk Assessment Tool, which calculates future risk of CRC, to determine whether it could be used to predict current advanced neoplasia\xa0(AN) in a veteran cohort undergoing a baseline screening colonoscopy.MethodsThis was a prospective assessment of the relationship between future CRC risk predicted by the NCI tool, and the presence of AN at screening colonoscopy. Family, medical, dietary and physical activity histories were collected at the time of screening colonoscopy and used to calculate absolute CRC risk at 5, 10 and 20\u2009years. Discriminatory accuracy was assessed.ResultsOf 3121 veterans undergoing screening colonoscopy, 94% had complete data available to calculate risk (N\xa0=\u20092934, median age 63\u2009years, 100% men, and 15% minorities). Prevalence of AN at baseline screening colonoscopy was 11 % (N\xa0=\u2009313). For tertiles of estimated absolute CRC risk at 5\u2009years, AN prevalences were 6.54% (95% CI, 4.99, 8.09), 11.26% (95% CI, 9.28-13.24), and 14.21% (95% CI, 12.02-16.40). For tertiles of estimated risk at 10\u2009years, the prevalences were 6.34% (95% CI, 4.81-7.87), 11.25% (95% CI, 9.27-13.23), and 14.42% (95% CI, 12.22-16.62). For tertiles of estimated absolute CRC risk at 20\u2009years, current AN prevalences were 7.54% (95% CI, 5.75-9.33), 10.53% (95% CI, 8.45-12.61), and 12.44% (95% CI, 10.2-14.68). The area under the curve for predicting current AN was 0.60 (95% CI; 0.57-0.63, p\xa0<\u20090.0001) at 5\u2009years, 0.60 (95% CI, 0.57-0.63, p\xa0<\u20090.0001) at 10\u2009years and 0.58 (95% CI, 0.54-0.61, p\xa0<\u20090.0001) at 20\u2009years.ConclusionThe NCI tool had modest discriminatory function for estimating the presence of current advanced neoplasia in veterans undergoing a first screening colonoscopy. These findings are comparable to other clinically utilized cancer risk prediction models and may be used to inform the benefit-risk assessment of screening, particularly for patients with competing comorbidities and lower risk, for whom a non-invasive screening approach is preferred.