Clinical evidence for the adenoma-carcinoma sequence.

A review is given on evidence supporting or rejecting the hypothesis of a colorectal adenoma-carcinoma sequence. The majority of studies discuss adenomas from a clinical point of view, but pathology has also been considered in detail, and molecular biology has been touched on. It is concluded the adenoma stage is, most probably, a phase on the way to carcinoma. But it remains to be shown what effect the removal of adenomas will have in the long run on the incidence of colorectal carcinoma.