RELATIONSHIP BETWEEN MORPHOLOGICAL DIVERSITY AND AGNORS OR CATHEPSIN-B EXPRESSION IN COLORECTAL CANCERS

The biological characteristics associated with the morphological diver sity of colorectal cancers were investigated to elucidate the causes o f this diversity. We examined the proliferative and infiltrating activ ity of tumor cells, indicated by the mean number of Ag nucleolar organ izer region associated proteins (NORs) per nucleus (MNA) and the immun ohistochemical response to cathepsin B(CB), in various morphological t ypes of early and advanced colorectal cancers. We examined 73 colorect al cancers obtained by endoscopic and surgical resection. MNA values f or sessile and flat-elevated cancers were greater than the values for pedunculate, subpedunculate, and flat-or-depressed early cancers (sess ile, P < 0.05). In advanced cancers invading the muscularis propria, p rotruding cancers showed significantly higher MNA values than small ul cerative cancers (P < 0.01). CB expression increased significantly wit h the progression of colorectal cancers (P < 0.01), but was not relate d to morphological diversity in early and advanced cancers. In both se ssile and flat cancers, CB expression was higher in moderately differe ntiated than in well differentiated adenocarcinomas. These results ind icate that, in colorectal cancers, protruding early cancers without st alks and protruding advanced cancers have higher proliferative activit y than pedunculate or flat early cancers and small ulcerative advanced cancers, respectively, and that CB expression is not associated with morphological diversity, but with depth of invasion and histological d ifferentiation.