Background: Tailoring screening to colorectal cancer (CRC) risk could improve screening effectiveness. Most CRCs arise from advanced neoplasia (AN) that dwells for years. To date, no available colorectal neoplasia risk score has been validated externally in a diverse population. The authors explored whether the National Cancer Institute (NCI) CRC risk-assessment tool, which was developed to predict future CRC risk, could predict current AN prevalence in a diverse population, thereby allowing its use in risk stratification for screening.
Methods: This was a prospective examination of the relation between predicted 10-year CRC risk and the prevalence of AN, defined as advanced or multiple (≥3 adenomatous, ≥5 serrated) adenomatous or sessile serrated polyps, in individuals undergoing screening colonoscopy.
Results: Among 509 screenees (50% women; median age, 58 years; 61% white, 5% black, 10% Hispanic, and 24% Asian), 58 (11%) had AN. The prevalence of AN increased progressively from 6% in the lowest risk-score quintile to 17% in the highest risk-score quintile (P = .002). Risk-score distributions in individuals with versus without AN differed significantly (median, 1.38 [0.90-1.87] vs 1.02 [0.62-1.57], respectively; P = .003), with substantial overlap. The discriminatory accuracy of the tool was modest, with areas under the curve of 0.61 (95% confidence interval [CI], 0.54-0.69) overall, 0.59 (95% CI, 0.49-0.70) for women, and 0.63 (95% CI, 0.53-0.73) for men. The results did not change substantively when the analysis was restricted to adenomatous lesions or to screening procedures without any additional incidental indication.
Conclusions: The NCI CRC risk-assessment tool displays modest discriminatory accuracy in predicting AN at screening colonoscopy in a diverse population. This tool may aid shared decision-making in clinical practice. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2663-2670. © 2016 American Cancer Society.
Keywords: colon cancer; early detection; prediction; risk-stratification; screening.
© 2016 American Cancer Society.