Immunohistochemical study of GATA-3 expression versus estrogen and progesterone receptor in invasive mammary carcinomas

Background Estrogen receptor (ER)-positive and progesterone receptor (PR)-positive breast tumors are characterized by a gene expression profile exhibiting profound differences from that of ER and PR-negative tumors. GATA-3 gene expression is correlated with ER in breast cancer. Aim We aimed to evaluate immunohistochemically the expression of GATA-3 in invasive breast carcinoma, comparing this with ER and PR status and available clinicopathological features, and also to detect the association between GATA-3 and the included breast cancer molecular subtypes. Materialsand methods Fifty invasive breast carcinomas were studied for immunohistochemical demonstration of GATA-3 in the tumor cells. Cases were classified into two equal groups: group 1, that is, ER and PR positive, and group 2, that is, ER and PR negative. Molecular subtyping was applied. Results GATA-3 expression was detected in 88% of cases of group 1 and 56% of cases of group 2, showing direct association with ER and PR (P=0.031) and also significant association with luminal-like breast tumors. In addition, GATA-3 showed an inverse association with Ki-67 (P=0.0269); however, GATA-3 failed to show significant association with any of the clinicopathological parameters. Conclusion GATA-3 is an important luminal marker showing strong association with ER and PR in breast cancers, suggesting being a promising new breast-specific immunomarker that could be used for detection of breast cancer origin in metastatic tumors.