Estroma e neoplasias ovarianas: papel da alfa-actina de músculo liso e da proteína alfa de ativação dos fibroblastos

Abstract

Introduction: Ovarian cancer is one of the types of gynecological tumors that cause more deaths worldwide, presenting a small overall survival rate. It is an insidious disease and it is commonly diagnosed in more advanced stages, and may present a rapid evolution. Studies show that tumor growth is not only determined by malignant cells, since the interactions between cancer cells and the stromal compartment have important impacts on the growth and progression of cancer. The most important cell types in the tumor stroma are the fibroblasts associated with cancer. According to retrospective studies, they play an important functional role in relation to cells in the processes of metastasis and progression due to cell-to-cell interaction and soluble factors, responsible for the secretion of cytokines, extracellular matrix components and chemokines. Objectives: The aims of the study were to investigate two cancer-associated fibroblasts markers, alpha-smooth muscle actin (α-SMA) and fibroblast activation protein alpha (FAP), in the stromal compartment of benign and malignant ovarian epithelial neoplasms, and to relate their tissue expression with prognostic factors in ovarian cancer. Materials and Methods: We prospectively evaluated 56 patients who underwent surgical treatment for ovarian cyst and with a confirmed diagnosis of ovarian neoplasia. The 10 immunohistochemical study was performed for α-SMA e FAP. The prognostic factors were evaluated using Fisher's Exact Test. The level of significance was less than 0.05. Results: Fifty-six patients were evaluated, 28 had malignant ovarian neoplasms and 28 benign neoplasms. FAP immunostaining was stronger in ovarian cancer when compared to benign neoplasms (0.0366). In ovarian cancer, FAP stainings 2/3 was significantly related to histological grades 2 and 3 (p = 0.0183). There was no significant difference in relation to the other prognostic factors studied. Conclusion: FAP immunostaining is more intense in malignant neoplasms than in benign ovarian neoplasms, as well as in moderately differentiated and undifferentiated ovarian carcinomas compared to well differentiated neoplasms, suggesting to be a marker of worse prognosis.