Colon polyps and cancer.

Several important studies on screening for colorectal neoplasia were published in 1998-99, including average-risk as well as high-risk groups, and different strategies such as endoscopy, fecal occult blood tests, and other more specific markers of neoplasia. Some of these studies included the use of interventions other than initial screening and polypectomy; a few dealt with diagnostic methods in symptomatic patients, and the new diagnostic tool of virtual colonoscopy was highlighted by several authors. Endoscopic treatment for large adenomas and early colorectal cancer has become more widespread, but clearly it has limitations. Current discussion of the topic of colorectal polyps and cancer is largely based on the concept of the adenoma-carcinoma sequence, which is thought to be the most probable pathogenesis for colorectal cancer.