BACKGROUND & AIMS: Age, sex, smoking, and family history are risk factors for colorectal cancer in Asia. The Asia-Pacific Colorectal Screening (APCS) scoring system was developed to identify subjects with a high risk for advanced neoplasm (AN). We tested an algorithm that combined APCS scores with fecal immunochemical test (FIT) in colorectal cancer screening.
METHODS: We performed a multicenter prospective study, enrolling asymptomatic individuals older than 40 years old in 12 Asia-Pacific regions from December 2011 to December 2013. APCS scores were calculated for each individual (0-1 = low risk [LR], 2-3 = medium risk [MR], and 4-7 = high risk [HR] for AN). LR and MR subjects were offered FIT and referred for early colonoscopies if FIT results were positive. HR subjects were offered colonoscopies. The proportions of subjects with ANs were determined for each group based on colonoscopy findings; odd ratios for LR and MR subjects were calculated compared to LR individuals. We calculated the sensitivity of the APCS-FIT algorithm in identifying subjects with AN.
RESULTS: A total of 5657 subjects were recruited: 646 subjects (11.4%) were considered LR, 3243 subjects (57.3%) were considered MR, and 1768 subjects (31.3%) were considered HR for AN. The proportions of individuals with an AN in these groups were 1.5%, 5.1%, and 10.9%, respectively. Compared with LR group, MR and HR subjects had a 3.4-fold increase and a 7.8-fold increase in risk for AN, respectively. A total of 70.6% subjects with AN (95% confidence interval: 65.6%-75.1%) and 95.1% subjects with invasive cancers (95% confidence interval: 82.2%-99.2%) were correctly instructed to undergo early colonoscopy examination.
CONCLUSIONS: The APCS scoring system, which is based on age, sex, family history, and smoking, is a useful tool for determining risk for colorectal cancer and advanced adenoma in asymptomatic subjects. Use of the APCS score-based algorithm in triaging subjects for FIT or colonoscopy can substantially reduce colonoscopy workload.