Colorectal cancers, screening in the general population: Focusing

Abstract

Colorectal cancers are common throughout the world, although their incidence varies across continents and countries. 28% of these cancers are rectal and two-thirds of the remaining 72% are of left colonic location. Screening and prevention have proven effective in reducing the incidence of these cancers and their mortality. The best screening results in the so-called average-risk general population have been obtained in the USA, where first-line endoscopy is the gold standard when in other countries, especially European ones; screening was done by the search for occult blood in the stool. This group, however, became heterogeneous due to the intervention of environmental factors and co- morbidities; a colonoscopy is then proposed to those subjects considered at average risk. Virtual colonoscopy has excellent sensitivity and specificity for one centimeter polyps. The serrated polyps, pre-cancerous lesions predominating on the right, are more difficult to detect.