Abstract: Objective The aim of this study was to compare the application effects of two risk assessment models in the early screening of colorectal cancer,and to explore an evaluation model that was more suitable for the early screening of colorectal cancer in Chinese residents. Methods The 40-74 years old permanent residents who participated in the urban cancer early diagnosis and early treatment project in Nanshan District,Shenzhen from 2017 to 2019 were selected as the research subjects.Two risk assessment models were used to assess the risk of colorectal cancer in the same population and compare the screening performance and predicted value. Results A total of 4 141 participants were included,with an average age of 56.4±9.0 years old.The positive rates of model 1 and model 2 were 15.2% and 21.3%,respectively,and the overall agreement rate was 93.50%(Kappa value=0.784,P＜0.001).Among 702 colonoscopy examiners,the detection rates of enteritis,polyps,adenomas,CRC,and other intestinal lesions were 12.5%,12.0%,15.8%,0.7%,and 30.7%,respectively.There was no statistically significant difference in the distribution of colonoscopy results(χ²=8.679,P=0.123).The sensitivity of model 1 was 45.7%,which was lower than that of model 2(61.2%);while the specificity(64.8%),positive predictive value(76.7%),Kappa value(0.081)and Youden index(0.103)were higher than those in model 2(41.7%,72.6%,0.026 and 0.029).The areas under the ROC curves for the two models were 0.660(95% CI:0.618-0.702)and 0.675(95%CI:0.634-0.715),respectively,and there was no significant difference(P=0.584). Conclusion Both RAMs have certain predictive power and advantages for early diagnosis of CRC,but model 1 is slightly better than model 2 in terms of screening accuracy and screening benefit.In large-scale population screening,it is recommended the two models learn from each other′s strengths and complement their weaknesses,and are comprehensively applied.

Key words: Colorectal cancer, Risk assessment model, Screening, Early diagnosis and early treatment