The case for direct colonoscopy screening for colorectal cancer.

Recent large series of direct colonoscopy screening for colorectal cancer increase our understanding of the advantages of this approach, and have indirectly confirmed efficacy. When performed by well-trained, experienced endoscopists, colonoscopy screening is successful and safe. The prevalence of advanced neoplasia is low under the age of 50 yr but increases substantially with each decade of life thereafter at least until the age of 80 yr. Most detected cancers are at an early, curable stage. A substantial number of proximal advanced neoplasia are detected that would be missed by screening flexible sigmoidoscopy. Widespread population-based colonoscopy screening would markedly decrease the incidence and mortality of this major malignancy. Issues of compliance and capacity related to direct colonoscopy have not yet been adequately addressed.