Adenoma Detection Rate in Average-Risk Population: An Observational Consecutive Retrospective Study

Background Although colonoscopy is considered the most effective tool for reducing colorectal cancer-related morbidity, the age at which average-risk individuals begin colonoscopic screening is undetermined. This study aimed to compare the adenoma and advanced adenoma detection rates according to age and sex in a large average-risk population in the rural areas of Eastern China. Methods This observational, single-center, retrospective study included patients with average colorectal cancer risk and examined the adenoma and advanced adenoma detection rates using age intervals of 5 years. We also compared the size and age of patients with and without advanced adenoma. Results We included 18 928 patients with a median age of 54 years (range 15–90 years), including 10 143 men and 8785 women. The adenoma and advanced adenoma detection rates were 17.08% and 5.24%, respectively, and increased with age in the whole population. The adenoma detection rates increased from 8.97% (aged 40–44) to 14.98% (aged 45–49) and 6.24% (aged 45–49) to 11.00% (aged 50–54) in men and women (both P < .001), respectively. The advanced adenoma detection rates increased from 2.19% (aged 40–44) to 4.76% (aged 45–49) and 1.89% (aged 45–49) to 3.13% (aged 50–54) in men ( P = .002) and women ( P = .056), respectively. Patients with advanced adenomas were significantly older than those with non-advanced adenomas ( P < .001). The tumors in the advanced adenoma group were significantly larger than those in the non-advanced adenoma group ( P < .001). Conclusion The adenoma and advanced adenoma detection rates increased significantly in average-risk population aged 45 years and older, especially in men.