Phenotypic expression of colorectal adenocarcinomas with reference to tumor development and biological behavior

The purpose of this study is to clarify the correlation between cell differ entiation and tumor development, including tumor aggressiveness and biologi cal behavior. Eighty-three cases of advanced colorectal adenocarcinoma were randomly selected. Using immunohistochemical staining with antibodies to C D10, MUC2 and human gastric mucin (HGM), the colorectal adenocarcinomas cou ld be classified into five types (18 small intestinal, 27 large intestinal, 2 gastric, 9 mixed and 27 unclassified). Each type had characteristic feat ures. The small-intestinal type showed a relatively lower incidence of lymp hatic permeation and higher venous invasion. The large-intestinal type show ed a low incidence of venous invasion and lymph node metastasis. The mixed type revealed female and right-side-dominant distribution, large tumor size , high incidence of mucinous carcinoma, and low incidence of venous invasio n. Gastric type was seen in only two cases (2%), which exhibited high histo logic grade, lymphatic permeation and lymph node metastasis with no venous invasion. Such phenotypic classifications are considered to be useful not o nly for evaluation of the biological behavior of the carcinoma, but also fo r analysis of tumorigenesis.