Resumo:
Breast tumors in dogs are frequent and about 50% are carcinomas, constituting an
interesting study model for humans, given the clinical, biological and genetic
similarities between species. GATA3 is a transcription factor of the GATA family that
regulates the differentiation of different types of tissues, assuming the greatest
expression in the mammary gland. Research in the field of human breast disease
suggests that GATA3 plays an important role in tumor differentiation and its expression
decreases with the increase in tumor grade. The objective of this study is to evaluate the
expression of GATA3 and its correlation with prognostic factors and survival. Forty
breast tumor samples were collected from bitches, 10 of which were benign tumors, 20
were mixed tumor carcinomas (MSC) subdivided into grade I and grade II and 10 cases
of aggressive tumors. An immunohistochemical panel was performed for each group
with the Ki-67, RE and GATA-3 markers. Subsequently, the correlation of GATA-3
with prognostic factors and survival was evaluated. As a result, animals with benign
tumors, and well-differentiated carcinomas, showed greater expression of GATA-3. ER
expression was directly proportional to GATA3 marking, with a strong correlation in all
groups, while Ki-67 expression was inversely proportional to a strong correlation in
CTM grade I, CTM grade II and aggressive tumor groups. Animals diagnosed with
tumors with high GATA3 expression had better survival. GATA3 has a potential
prognosis to define the outcome of female dogs with mammary neoplasm. In the
multifactorial analysis, GATA3 presented p <0.05 for survival, estrogen receptor (ER),
Ki-67 and histopathological grading. Therefore, the analysis of the results gives GATA3 a potential independent prognostic value for survival, in addition, this biomarker
predicts the outcome of female dogs with mammary neoplasm.
