The Morphological Features of “Cavitary” Type Angiogenesis in Diffuse and Intestinal Types of Gastric Cancer and Its Relationship with Tumor-Infiltrating Immune Cells

Abstract

Background: Previously we have described the "cavitary” type of angiogenesis by gastric cancer (GC) consisting of the formation of “cavitary structures” (CS) in tumor stroma, which are then lined by endothelial cells and merged into the blood vessels of the organ. The morphological features of the "cavitary” type of angiogenesis in intestinal and diffuse types of GC and the relations of CS with the tumor-infiltrating immune cells, was the purpose of this study. Materials and Methods: The samples of tumor and adjacent gastric mucosa (GM) in 73 patients with GC who had undergone radical surgery were being studied. The sections were stained with hematoxylin and eosin and immunohistochemically using antibodies to CD34, CD4, CD8, CD20 и CD68. Results: The differences of “cavitary” type of angiogenesis in the intestinal and diffuse types of GC are only associated with CS type-1 that are formed as a result of the abruption of epithelial cells from the underlying stroma. In the intestinal type of GC the basis for the formation of CS type-1 are the tumor glands. The wall of such CS is most likely the basement membrane bordering the connective tissue. In the diffuse type of GC the CS type-1 are presented as the structures limited from outside by the tumor cells. In their lumen the fragments of tumor tissue having the same structure as the surrounding one are being detected. The performed analysis showed that the number of CS type-1 was associated with the density of CD68, whereas the presence of CS type-2 – with the presence of lymphoid follicles (LF) and B-cell infiltrations at the boundary of tumor and GM. The density of CD68 in GM was higher in cases with multiple CS type-1 (72.6±47.0 vs. 41.6±15.4 cells per unit area, P= .03). In turn, CS type-2 were more often met in the presence of multiple LF (72,3% vs. 33,3%, P= ,04) and B-cell infiltrations (90% vs. 26,3%, P= ,001). Conclusion: The obtained data testify about the relation of CD20 lymphocytes and CD68 macrophages with the "cavitary” type of angiogenesis.