Validation of the NCI Colorectal Cancer Risk Assessment Tool for baseline advanced neoplasia in a veterans cohort.
Musselwhite, LW; Redding, TS; Hauser, ER; Lieberman, DA; Provenzale, DT
Published in: Journal of Clinical Oncology
521 Background: Tailoring screening strategy to colorectal cancer (CRC) risk may improve efficiency for all stakeholders. We applied the National Cancer Institute (NCI) CRC Risk Assessment Tool, which calculates 5-10-year, and 20-year absolute risk of colorectal cancer to determine whether it could be used to predict baseline risk of colorectal cancer precursors in a Veterans cohort undergoing first screening colonoscopy. Methods: This was a prospective evaluation of whether the NCI CRC Risk Assessment Tool which offers an absolute risk over time, could be used to estimate baseline cancerous precursors (advanced neoplasia) in Veterans undergoing first screening colonoscopy. Family, medical, dietary and physical activity histories were collected at the time of screening colonoscopy and used to calculate absolute 5, 10, and 20-year CRC risk, and to compare estimated CRC risk to observed AN. Sensitivity analyses were performed. Results: Of 3,121 Veterans undergoing screening colonoscopy, 94% had complete data available to calculate risk (N = 2,934, median age 63 years, 100% men, and 15% minorities). 11% (N = 313) were diagnosed with AN on baseline screening colonoscopy. The area under the curve for predicting 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. At 5 years, we calculated the sensitivity (0.18, 95% CI; 0.14-0.22), specificity (0.91, 95% CI; 0.90-0.92) positive predictive value (0.19, 95% CI; 0.15-0.24) and negative predictive value (0.90, 95% CI; 0.89-0.91) considering the top 10 percentile of risk tool scores as a positive result. Conclusions: The NCI CRC Risk Assessment Tool had modest discriminatory function for predicting AN risk at 5, 10 and 20 years. The Tool’s specificity and negative predictive value were quite good, highlighting its usefulness in risk prediction. This tool may beused to inform the benefit-risk assessment of screening colonoscopy for patients with competing comorbidities.
