[Macroscopic observation of progression of colorectal cancer]

Resected or polypectomized materials of colo-rectal cancer are morphologically analyzed in order to estimate their developing pattern. A retrospective review of previous radiological or endoscopic findings is also made in the patients who had either or both of examinations in the past. Morphologically, a distribution chart of colo-rectal cancers by their size and height is made, and a zone of colo-rectal cancers with the same morphological features is drawn. Retrospectively, type 1 advanced cancer appears to develop from Is type early cancer, and morphologically, a zone of Is type early cancers and that of type 1 advanced cancers partly overlap each other. The retrospective review also suggests that type 2 advanced cancer seems to develop from type Is, IIa or IIa + IIc early cancer. On the distribution chart, a zone of type 2 advanced cancer is partly superimposed over or bordered by that of early cancers type Is, IIa or IIa + IIc. Thus, it may fairly be said that advanced cancer develops from early cancer with its zone on the distribution chart partly superimposed over or bordered by that of the advanced cancer. Among early cancers, sessile type, superficial elevated type or elevated type with central depression may develop to advanced cancer. Both morphological analysis and retrospective radiological or endoscopic review of colo-rectal cancers would suggest the developing pattern of pedunculated or flat type early cancer.