Expressão dos elementos estromais dos adenocarcinomas prostáticos nos diferentes escores de Gleason

Abstract

The classification of prostate cancer into grades by Gleason is a well-established indicator that has endured the test of time. However, it is a subjective method and based exclusively on the characteristics of parenchyma. The evaluation and algorithm classification is based on two fundamental criteria: the degree of glandular differentiation and tumor development architectural pattern. The objective of this study was to quantify and compare the expression of stromal elements in prostate adenocarcinoma with different Gleason scores with non-tumor tissue (control), corroborating with the data of the parenchyma and the Gleason s classification. Surgical specimens from radical prostatectomy (n = 133) were processed for paraffin embedding and constructed a TMA matrix with fragments of adenocarcinoma and non-tumor tissue. The sections were stained with hematoxylin & eosin, Masson's trichrome, Weigert for elastic fibers and immunohistochemical technique to vessels. These elements were identified and quantified as percentage by using the Image-J software. We observed significant stromal changes that corroborate the derangement of parenchyma found in higher Gleason grades. Significant differences in the elements analyzed only started to appear from Gleason 7. The smooth muscle fibers were significantly decreased in samples with Gleason 7. In samples with higher Gleason (8-10), three of the parameters analyzed presented significant differences: smooth muscle decreased while and elastic fiber system and vessels increased. This study revealed that there is a significant difference between the extracellular matrix in prostate cancer compared to the non-tumor area (control) especially in Gleason 7. In addition, our data showed that important modifications of the prostatic stromal elements strongly correlate with different Gleason scores and can contribute to predict the pathological staging of prostate cancer. Also, these data can contribute for the studies of the morphological substrate of prostate cancer applied to new prognostic proposal.