Pancitoqueratina, KI-67 e leucócitos como fatores prognósticos para neoplasmas mamários em cadelas

Abstract

In Veterinary Medicine, mammary neoplasms are of great importance, because in addition to serving as an experimental model for the biological study of cancer in humans, they are the most common type in female dogs. Although the histopathology technique allows the definitive morphological diagnosis of the type of neoplasm, biomarkers are beginning to be increasingly used and studied as prognostic factors. In addition, the inflammatory cells involved in the neoplastic alteration can lead to increased metastasis and progression of the neoplasm, demonstrating the relevance of the study regarding the association of defense cells in the animal organism and in the intratumoral environment. Through the evaluation of the pathological, clinical and biological aspects, both of the patient and of the neoplasm, it is possible to predict the survival time of the animals, the probability of recurrence and the evolution of the clinical condition. Thus, this work aimed to study certain biomarkers and defense cells as prognostic factors for mammary neoplasms in female dogs assisted in the Southwest of Paraná. Twenty-six female dogs submitted to unilateral mastectomy in a teaching hospital of a higher education institution were selected, and data were collected about the preoperative leukogram, clinical staging and clinical evaluation of the patients. The mammary glands resulting from the unilateral radical mastectomy were fixed in 10% formalin and histopathological slides (hematoxylin and eosin) and immunohistochemistry were made for later microscopic evaluation. The glands were classified according to Zappulli et al (2019) and the defense cells of the tumor environment were evaluated. In immunohistochemistry, the KI-67 marker was used in all mammary glands and anti-cytokeratin protein (Clone AE1/AE3) in lymph nodes of 15 patients. The data obtained were tabulated in an Excel spreadsheet and descriptive statistical analysis was performed, as well as the chi-square test and Analysis of Variance in the PSPP program version 1.6.2, considering p< 0.05. In that study, 96.15% of the bitches had malignant neoplasms, of which 80.76% were not spayed and 57.69% received injectable exogenous contraceptives. The correlation between clinical staging and tumor size was not significant, as well as the staging and aggressiveness of the neoplasm, although the identification of alterations in the lymph node was observed. Through the histopathological evaluation, the presence of lesions adjacent to the primary tumor was verified, even though these were not identified in the physical examination. Malignant lesions were the most diagnosed in the breast tissue (46%), followed by pre-neoplastic (38.6%) and benign (16%). In the classification of malignant lesions, grade I had the highest sample (82.22%). Defense cells were identified in all mammary gland lesions and their type, location and intensity were related to tumor progression and therefore were evaluated according to each patient. The preoperative leukogram was not related to the defense cells of the intratumoral environment, which suggests that these alterations are Paraneoplastic Syndromes (PS). The pancytokeratin marker was effective in detecting metastases in relation to routine HE examination. KI-67 expression was found to be prognostically effective to assess neoplasm proliferation. The Lymphocyte to Monocyte Ratio (RLM) and the Neutrophil to Lymphocyte Ratio (RNL) were significant to assess tumor proliferation and progression. The animal must be evaluated individually to maintain its well-being, as well as, more studies are needed regarding the accuracy of prognostic factors in Veterinary Medicine.