Development and validation of a risk stratification-based screening model for predicting colorectal advanced neoplasia in Korea.

GOALS: To develop and validate a risk stratification-based screening model for predicting colorectal advanced neoplasia in Korea.
BACKGROUND: Colorectal advanced neoplasia is the relevant finding of screening colonoscopy. Risk estimation for advanced neoplasia may be helpful to improve compliance and to develop more cost-effective approaches toward screening. STUDY: We developed Korean Colorectal Screening (KCS) score by optimizing and adjusting Asia-Pacific Colorectal Screening (APCS) score to predict advanced neoplasia in an asymptomatic Korean population who received screening colonoscopies from September 2006 to September 2009. Moreover, we validated the KCS score in another Korean cohort who received screening colonoscopies from October 2009 to February 2011. We also assessed the predictive power and diagnostic performance of both KCS and APCS scores.
RESULTS: There were 3561 subjects in the derivation cohort and 1316 subjects in the validation cohort, with a prevalence of advanced neoplasia of 4.7% and 4.3%, respectively. After a multivariate analysis, KCS was developed as 0 to 8 points comprising of age, sex, body mass index, smoking, and family history of CRC. Using KCS scores to stratify the validation cohort, the prevalences of advanced neoplasia in the 3 risk tiers (average, moderate, and high) were 2.0%, 3.7%, and 10.9%, respectively. Moderate-risk and high-risk tiers showed 2.1- and 6.5-fold increased prevalences, respectively, of advanced neoplasia compared with average risk tier. In addition, KCS score showed relatively good discriminative power (ROC=0.681) and higher sensitivity compared with APCS score for the high-risk tier.
CONCLUSIONS: KCS score may be clinically simple and useful for assessing advanced neoplasia risk in Korea. However, racial disparity should be considered in risk stratification-based screening in each country.