Improvement of Asia-Pacific Colorectal Screening score and evaluation of its use combined with fecal occult blood test

Background The Asia-Pacific Colorectal Screening (APCS) score is effective to screen high-risk groups of advanced colorectal neoplasia (ACN) patients but needs revising and can be combined with the fecal occult blood test (FOBT). This paper aimed to improve the APCS score and evaluate its use with the FOBT in stratifying the risk of ACN. Methods This prospective and multicenter study enrolled 955 and 1201 asymptomatic Chinese participants to form the derivation and validation set, respectively. Participants received the risk factor questionnaire, colonoscopy and immunochemical FOBT. Multiple logistic regression was applied, and C-statistic, sensitivity and negative predictive values (NPVs) were used to compare the screening efficiency. Results A modified model was developed incorporating age, body mass index (BMI), family history, diabetes, smoking and drinking as risk factors, stratifying subjects into average risk (AR) or high risk (HR). In the validation set, the HR tier group had a 3.4-fold (95% CI 1.8-6.4) increased risk for ACN. The C-statistic for the modified score was 0.69 ± 0.04, and 0.67 ± 0.04 for the original score. The sensitivity of the modified APCS score combined with FOBT for screening ACN high-risk cohorts was 76.7% compared with 36.7% of FOBT alone and 70.0% of the modified APCS score alone. The NPVs of the modified score combined with FOBT for ACN were 98.0% compared with 97.0% of FOBT alone and 97.9% of the modified APCS score alone. Conclusions The modified score and its use with the FOBT are efficient in selecting the HR group from a Chinese asymptomatic population.