| [ Summary ] |
In order to clalify the morphogenetic background of colorectal cancers less than 2cm in diameter, we histopathologically classified colorectal cancers into non-protruted(NP) and protruted(P) types. NP types were classified into two subtypes; intermediate(I) and typical NP. We investigated the K-ras point mutations and immunoreactivities of p53 and adhesion molecules beta-catenin and E-cadherin) in colorectal cancers, Morphopathologically, many cases of colorectal cancers less than 2cm in diameter showed NP type, and typical NP type cancers showed no K-ras mutation. In many cases of typical NP cancers and I type cancers less than 2cm in diameter, menbranous (normal) immunoreactivities of adhesion molecules decreased in comparison with P type cancers, These results suggest that most of colorectal cancers less than 2cm in diameter may be derived from depressed type early cancers, and NP type cancers may have more invasive potential than P type cancers. |