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 (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 years. Discriminatory accuracy was assessed.ResultsOf 3121 veterans undergoing screening colonoscopy, 94% had complete data available to calculate risk (N = 2934, median age 63 years, 100% men, and 15% minorities). Prevalence of AN at baseline screening colonoscopy was 11 % (N = 313). For tertiles of estimated absolute CRC risk at 5 years, 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 years, 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 years, 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 < 0.0001) at 5 years, 0.60 (95% CI, 0.57-0.63, p < 0.0001) at 10 years and 0.58 (95% CI, 0.54-0.61, p < 0.0001) at 20 years.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.

From Algorithms to Clinical Utility: A Systematic Review of Individualized Risk Prediction Models for Colorectal Cancer

“…Other biases included non-blinding of predictor and outcome assessment, improper use of statistical methods (including the use of univariate analysis for predictor selection and neglecting competing risk), and inadequately small sample sizes. Furthermore, a total of 15 studies raised applicability concerns, which were uniformly linked to the specific selection of participants based on FIT results or their pre-existing cardiovascular disease [41,50,57,[61][62][63][64][65]67,72,76].…”

“…2023, 5, FOR PEER REVIEW 8 neglecting competing risk), and inadequately small sample sizes. Furthermore, a total of 15 studies raised applicability concerns, which were uniformly linked to the specific selection of participants based on FIT results or their pre-existing cardiovascular disease [41,50,57,[61][62][63][64][65]67,72,76].…”

“…There are two main categories of risk models for predicting CRC or AN based on their predictor features: (1) conventional risk model, which uses known and well-established risk factors for CRC; and (2) composite model, which combines well-established risk factors with more advanced features, such as test/laboratory findings and genetic factors. Among the 41 included studies, we identified 22 original conventional risk models, [36][37][38]40,45,48,50,51,53,54,58,59,61,[63][64][65][67][68][69][70]72,74] and 13 composite models [39,[41][42][43][44]47,56,57,62,71,73,75,76]. Of these, three conventional risk models have undergone external validation in separate studies: (1) the Asia-Pacific Colorectal Screening (APCS) model [45], validated in four other studies [46,49,66,70];…”

“…(2) Kaminski's risk scores [60,69], validated in one study; and (3) The National Cancer Institute-Colorectal Cancer (NCI-CRC) risk assessment tool [77], validated in one study [78]. Eight other studies conducted external validation in the original publication, including six conventional risk models [37,48,63,65,67] and three composite models [41,56,76].…”

“…For women, hormone-replacement therapy (HRT) and estrogen exposure based on menopausal status predictors were added. Following the initial publication, the model was externally validated among a veteran cohort undergoing baseline screening colonoscopy [63].…”