Poorly Differentiated Clusters in Colorectal Adenocarcinomas Share Biological Similarities with Micropapillary Patterns as well as Tumor Buds

摘要

In colorectal carcinoma, poorly differentiated clusters (PDCs) are a poor prognostic indicator and show morphological continuity and behavioral similarities to micropapillary patterns (MPPs) as well as tumor buds (TBs). Epithelial-mesenchymal transition (EMT) and inhibition of cancer-stromal interactions may contribute to the development of PDCs. To clarify the biological nature of PDCs, we examined immunohistochemical stainings for β-catenin, Ki-67, E-cadherin, epithelial cell adhesion molecule (EpCAM), MUC1, and epithelial membrane antigen (EMA), which are associated with EMT and cancer-stromal interactions. The expression frequencies and patterns of PDCs, TBs, and differentiated neoplastic glands from the tumor center (TC) were compared. In the study group (117 cases), the nuclear β-catenin staining index was higher in PDCs (37.3%) and TBs (43.3%) than in neoplastic glands from TC (8.9%, P Go to: Graphical