GATA3 and CK5/6 Immunohistochemical Expression in Urothelial Carcinoma: Diagnostic, Biological and Prognostic Significance

Abstract

Background: Urothelial carcinomas [UCs] can be diagnostically challenging, particularly transurethral bladder tumors resection biopsies with limited material. Immunohistochemistry is a valuable instrument for diagnosis when morphology alone is inadequate. GATA-binding protein 3 [GATA3] and cytokeratin 5/6 [CK 5/6] contributes to the growth of UC. However, their correlative expression in UC and prognostic value has not been sufficiently investigated. The aim of the work: The current study aimed to evaluate the utility of GATA3 expression in UC and correlate that with CK 5/6 expression to verify different subtypes of UC and assess their prognostic significance. Methodology: Here, we immunohistochemically stained GATA3 and CK 5/6 in 90 UCs samples by transurethral bladder tumor resection in a retrospective study, between May 2018 and February 2020. All were histopathologically evaluated and immunohistochemically stained for GATA3 and CK 5/6, and then correlated them with the clinicopathological parameters to investigate their clinical significance. Results: GATA3 expression was seen in 76 patients [84.44 %]. There was significant correlation between GATA3 expression with the tumor histological grade and degree muscle invasion. There was a weak or even negative expression in high‑grade, invasive than the low‑grade, non-invasive tumor [P= <0.001]. CK5/6 was positive and focally positive in 27.78% with a significant correlation of CK5/6 expression with tumor grade and muscularis propria invasion. On the other side, tumors with diffuse GATA3 expression had low CK5/6 expression. Conclusion: GATA3 and CK 5/6 should be used as sensitive and specific markers for UC. They can also be effectively used in the prediction of probable grade and tumor invasion in biopsied material with poor morphological characters; and thus, help in the future appropriate treatment.