Relação mastócitos e angiogênese em neoplasias mamárias caninas

Abstract

The mammary neoplasias are the most often tumor type in bitchs and women. Female dogs are considered an excelent spontaneous model in the breast cancer study. The tumor microenvironment has been studied in the recent years to a greater understanding of the development and progression of this disease. Mast cells are a cell type present in this microenvironment that can promote neoplasms by releasing pro-angiogenic factors present in their granules. Likewise, tumor fibrosis has been considered a prognostic factor in different types of tumors. The present work aims to verify the connection between mast cells and angiogenesis in different histological types of mammary tumors by measuring the role of degranulation and microlocation in canine mammary glands tumors. The analyzed mammary glands were splitted into three groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. The staining of the mast cells, the blood vessels and the tumor fibrosis were performed by histochemical techniques and evaluated by ImageJ software version 1.42q. The total density of vessels (p = 0.03) and peritumoral vessels (p = 0.05) were higher in the malignant group. There was even a positive correlation between the intratumoral and total vessels and the mast cell density. In the face of these findings, we can conclude that a higher density of mast cells is related to a higher density of blood vessels and that these are more abundant in malignant neoplasms reinforcing the crucial role of angiogenesis in neoplastic development.