Morphological and histological aspects of Placental tissue from pregnant Wistar rats bearing Walker 256 tumor. Evaluation of the effects of tumor growth and of exposure to chemotherapy treatment during pregnancy.

Abstract

Introduction: The incidence of cancer during pregnancy is significantly increased due to a number of factors, such as advanced maternal age, advances in therapy and preservation of fertility. This situation represents a major therapeutic challenge, since maternal and fetal/neonatal health need to be considered. The morphological alterations involved in the placenta during the association between cancer and pregnancy are still poorly explored, even with the high incidence of complications, such as preterm delivery and fetal growth restriction. Thus, the elucidation of changes in the placenta during neoplastic disease may bring possibilities for a better future therapeutic approach. In this line, pre-clinical experiments using animal models with Walker 256 carcinosarcoma, originally a mammary adenocarcinoma in a rat, could be used as tumor model during pregnancy. Objective: To identify the morphological and histological changes in the placenta of pregnant Walker 256 carcinosarcoma-bearing rats exposed to chemotherapy treatment. Materials and methods: Placental tissues will be collected from healthy pregnant Wistar rats (Control group) and from patients with Walker 256 tumor undergoing chemotherapy after the first third of pregnancy (Cancer group). + Chemotherapy). The placentas will be removed, weighed and photographed (maternal and fetal face). Placentas will have their area and volume calculated. After the photographic records, tissue sections from the basal plate (BP) will be properly embedded in paraffin and cut to a thickness of 4µm, the sections will be stained with hematoxylin/eosin to evaluate the histological aspect of the placental cells. For data analysis, Student's t tests will be considered, considering the comparison of the two experimental groups with continuous variables and normal distribution.