High-resolution endoscopy and early gastrointestinal cancer...dawn in the East.

Cancer in the esophagus, stomach, and large bowel accounted for 24 % of worldwide cancer mortality in 2002. This burden is expected to increase further as the world's population ages. Prevention is based on early detection of potentially curable cancers and/or precursor conditions that have a significant risk of progression to malignancy. Early detection in the asymptomatic population can be achieved in: (a) people who comply with interventions proposed by health authorities (population-based screening); (b) people with a link to a particular health policy (e. g. occupational screening); and (c) people who contact their own doctor or private health check-up institutions (individual or "opportunistic" screening). Factors that limit the benefit of early detection and treatment of neoplastic lesions include the degree of compliance with the selection procedure and compliance with recall for diagnosis and treatment in people with a positive test. The miss rate for small but potentially cancerous lesions is often responsible for interval cancers. There is also a danger of overdetection and overtreatment of lesions with a very low risk of progression to malignancy.