A risk-prediction score for colorectal lesions on 12,628 participants at high risk of colorectal cancer

Background The uptake of colonoscopy is low in individuals at risk of colorectal cancer (CRC). We constructed a risk-prediction score (RPS) in a large community-based sample at high risk of CRC to enable more accurate risk stratification and to motivate and increase the uptake rate of colonoscopy. Methods A total of 12,628 participants classified as high-risk according to positivity of immunochemical fecal occult blood tests or High-Risk Factor Questionnaire underwent colonoscopy. Logistic regression was used to derive a RPS and analysed the associations of the RPS with colorectal lesions, giving odds ratios (ORs) and 95% confidence intervals (CIs). Results Of the participants, men (OR = 1.73, 95% CI = 1.58-1.90), older age (>= 65 years; 1.41, 1.31-1.53), higher body mass index (>= 28 kg/m(2); 1.22, 1.07-1.39), ever smoking (1.47, 1.31-1.65), and weekly alcohol use (1.28, 1.09-1.52) were associated with a higher risk of colorectal lesions. We assigned 1 point to each of the above five risk factors and derived a RPS ranging from 0 to 5, with a higher score indicating a higher risk. Compared with a RPS of 0, a RPS of 1, 2, 3, and 4-5 showed a higher risk of colorectal lesions, with the OR (95% CI) being 1.50 (1.37-1.63), 2.34 (2.12-2.59), 3.58 (3.13-4.10), and 3.91 (3.00-5.10), respectively. The area under the receiver-operating characteristic curve of RPS in predicting colorectal lesions was 0.62. Conclusions Participants with an increase in the RPS of >= 1 point had a significantly higher risk of colorectal lesions, suggesting the urgency for measuring colonoscopy in this very high-risk group. High-risk strategies incorporating RPS may be employed to achieve a higher colonoscopy-uptake rate.