Evolution of cancer of the colon and rectum

Abstract

In this paper the opportunity is taken to describe the personal position of the speaker with respect to the evolution of cancer of the colon and rectum. A general account of the predisposing causes is presented, with emphasis on the malignant potential of adenomatous polyps and villous adenomas. The significance of the polyp–cancer sequence is discussed, and some evidence given about how long it takes for polyps to become cancerous. Some reference is also made to the etiologic significance of the polyp–cancer sequence. Do all cancers of the colon and rectum arise from adenomatous polyps or villous adenomas? An attempt will be made to answer this question and to review the alternatives to this mode of histogenesis.