Immunohistochemical expression of GATA3 in urothelial carcinoma of urinary bladder

Background and objective: GATA3, an emerging immunohistochemical marker, is a zinc finger transcription factor that is expressed in normal urothelial epithelium and its corresponding neoplasms, and it has been recognized as a reliable urothelial related immunohistochemical marker. This study aimed to detect the frequency of GATA3 expression in urothelial carcinoma of urinary bladder and determine its association with some clinicopathologic parameters. Methods: Seventy-nine formalin fixed paraffin embedded blocks of urothelial carcinoma cases were randomly selected from a private laboratory in Erbil city during October 2019 to October 2021. In this study, GATA3, a Rabbit monoclonal antibody was applied on urothelial carcinoma cases and its expression was assessed. Results: GATA3 was expressed in 94.9% of the study cases. It was expressed in all non-invasive and low-grade urothelial carcinoma cases and 97.1% of papillary urothelial carcinoma cases, while it down-expressed in high-grade, invasive and non-papillary urothelial carcinoma cases. A significant association was noted between GATA3 expression and tumor pattern (P = 0.034), while no significant association was noted between GATA3 expression and other clinicopathologic parameters like age, gender, tumor grade, lympho-vascular invasion and tumor stage. Conclusion: GATA3 is a useful diagnostic immunohistochemical marker for urothelial carcinoma, as this marker was expressed in 94.9% of urothelial carcinoma cases with a significant association with tumor pattern. Further studies are required to evaluate GATA3 expression in association with urothelial cancer progression and metastasis.