Abstract
Sixty-one early cancers of the large intestine were studied in order to know the developmental process of colorectal cancers. The distributions of early cancers of large intestine were compared with those of 640 adenomas and 378 advanced cancers. Early cancers were deviled into two groups accord-ing to their size above 10mm and 10mm or less. Early cancers sized 10mm or less were accompanied less frequently with adenomatous element in histology than larger lesions above 10mm in size. Grossly, 91% of small lesions showed flat or sessile in shape on endoscopy. Distributions of those small early cancers of large intestine were more similar to those of advanced cancers than those of large early cancers. Early cancers above l0mm in size distributed similarly to those of the large size adenomas above 10mm in diameter. Sessile small cancers investigated in this study are speculated to be lesions which cancerated in their early stage because of their histological features. We think that process of early cancerization is main route which progresses to the advanced cancer because of their similar distributions in the large intestine.
