Objective: The preferred method for screening asymptomatic people for colorectal cancer (CRC) is colonoscopy, according to the new American guidelines. The aim of our study was to perform a meta-analysis of the prospective cohorts using total colonoscopy for screening this population for CRC. We looked for the diagnostic yield of the procedure as well as for its safety in a screening setting.
Methods: We included papers with more than 500 participants and only those reporting diagnostic yield of adenoma (and/or advanced adenoma) and CRC. Nested analysis were performed for secondary endpoints of complications and CRC stages when this information was available. All analyses were performed with StatDirect Statistical software, version 2.6.1 ( http://www.statsdirect.com ).
Results: Our search yielded ten studies of screening colonoscopy conducted in asymptomatic people that met our inclusion criteria, with a total of 68,324 participants. Colonoscopy was complete and reached the cecum in 97% of the procedures. Colorectal cancer was found in 0.78% of the participants (95% confidence interval 0.13-2.97%). Stage I or II were found in 77% of the patients with CRC. Advanced adenoma was found in 5% of the cases (95% confidence interval 4-6%). Complications were rare and described in five cohorts. Perforation developed in 0.01% of the cases (95% confidence interval 0.006-0.02%) and bleeding in 0.05% (95% confidence interval 0.02-0.09%).
Conclusions: Our findings support the notion that colonoscopy is feasible and a suitable method for screening for CRC in asymptomatic people.