Colorectal neoplasia in Asia: a multicenter colonoscopy survey in symptomatic patients

Background: The incidence of colorectal cancer is rising rapidly in some Asian countries. Objective: To determine the prevalence and the distribution of colorectal neoplasm in Asian populations. Design: A multicenter colonoscopy survey. Patients: Between July 2004 and April 2005, consecutive symptomatic patients undergoing colonoscopic examinations in 10 different Asian countries. Setting: The location and the histologic features of all colonic neoplasms were recorded. Advanced neoplasm was defined as adenoma larger than 10 mm in size, with >25% villous features or with high-grade dysplasia or invasive carcinoma. Main outcome measurements: The prevalence and the distribution of colorectal neoplasm and advanced neoplasm. Results: A total of 5464 eligible patients underwent colonoscopy. Advanced neoplasm was found in 512 patients (9.4%). Factors associated with the presence of advanced neoplasm in this symptomatic Asian population included male sex (relative risk [RR] 1.52, 95% confidence interval [CI] 1.26-1.84), older age (RR 1.05, 95% CI 1.04-1.06), and ethnicity (P = .001). Advanced proximal neoplasm was detected in 136 patients (2.5%); 83 (61.0%) of the patients had normal distal colon. The RR of proximal advanced neoplasm was 2.5, 95% CI 1.7-3.7 in those with any adenoma in the distal colon compared with those with normal distal colon. Limitations: Possible underrepresentation of some ethnic groups because of uneven ethnic group distribution and the lack of population-based registry. Conclusions: This was the first multicenter colonoscopy survey that examined the characteristics of colorectal neoplasm in Asia. The results will have important implications on the planning for future colorectal cancer screening in this region.restrictio