Prevalence and characteristics of colonic adenoma in mainland China

Background and aim: To investigate the prevalence and characteristics of colonic adenoma and advanced colonic adenoma in a large group of patients in mainland China.

Materials and methods: We conducted a cross-sectional study on patients who had undergone colonoscopy examination in a university hospital in mainland China. Colonic adenomas and advanced adenomas were recorded.

Results: The prevalence of polyps, adenoma, and advanced adenoma was 23.9%, 13.3%, and 3.5%, respectively. Age and sex were independent risk factors for the prevalence of adenoma and advanced adenoma. Polyp size was associated with an increased risk of both colonic adenoma (OR 1.50, 95% CI 1.44-1.56) and advanced adenoma (OR 2.78, 95% CI 2.55-3.03) after sex and age adjustment. Proximal colon polyps were a risk factor for adenoma (OR 1.41, 95% CI 1.20-1.66) and also associated with a significant reduction (44%) in risk of advanced adenoma (OR 0.56, 95% CI 0.36-0.86) compared to distal colon adenoma after sex and age adjustment. A screening indication was associated with a statistically significant decrease in the odds of prevalence of adenoma (OR 0.90, 95% CI 0.81-0.99) and advanced adenoma (OR 0.72, 95% CI 0.59-0.88) compared to a no-screening indication.

Conclusion: The overall prevalence of adenoma was low in mainland China. It exhibited a varied pattern with respect to age and sex. Polyp size was a risk factor for both colonic adenoma and its transition to advanced adenoma. Proximal colon polyps were a risk factor for adenoma, but a protective factor for advanced adenoma compared to distal colon adenoma.