Banca de DEFESA: MATHEUS MEDEIROS NUNES

EVOLUTIONARY HISTOPATHOLOGICAL ANALYSIS OF CARCINOGENESIS INDUCED IN THE ORAL CAVITY, ESOPHAGUS AND STOMACH OF RATS

Carcinogenesis; Wistar rat; 4-NQO; Histomorphometry; Carcinoma.

The complexity of carcinogenesis requires detailed studies to assist in its understanding. The objective of the present study was to carry out the chemical induction of carcinogenesis, analyzing the histopathological evolution of epithelial changes that culminate in the appearance of Epidermoid Carcinoma in different regions of the digestive tract (oral cavity, esophagus and stomach) with different induction times. We used male Wistar rats as an experimental model of carcinogenesis induced by the compound 1-oxide 4 nitroquinoline (4-NQO), with histopathological analysis of the cases studied to establish the diagnosis, as well as histomorphometric analysis to obtain the area of the lesion. Correlating with the measurement of rat weights during the carcinogenesis induction process. Our sample consisted of two groups, one group at 8 weeks (G8) and a second group at 12 weeks (G12). At the end of the induction time, the groups were euthanized and the studied organs were removed, namely: Tongue and palate (oral cavity), esophagus and stomach, all of which were subjected to laboratory processing to create histopathological slides. In the histopathological analysis, we observed the presence of hyperkeratinization, and different degrees of dysplasia, the formation of squamous cell carcinoma in the tongue, palate, and esophagus was also described, while in the stomach, epithelial erosion was observed. Furthermore, we found that the neoplastic lesions appeared as well-differentiated carcinomas. The data on weight and lesion areas were normally distributed [Kolmogorov-Smirnov] and the ANOVA test was used for the lesion areas and showed a significant difference for the organ, therefore the Post-Hoc test was suggested. has a lesion area larger than the tongue, palate and stomach. The induction model proved to be effective for the formation of lesions for experimental carcinogenesis studies, highlighting the importance of these studies for understanding and substantiating oncological processes in humans.