Expression of GATA3 and Cytokeratin 14 in Urinary Bladder Carcinoma (Histopathological and Immunohistochemical Study)

BACKGROUND: Urothelial carcinoma (UC) with squamous differentiation (SD) is the most common histologic variant of bladder carcinoma and its presence is associated with poor prognosis which may need early radical cystectomy to avoid progression and recurrence. It is difficult to detect few foci of SD, especially nonkeratinizing or early switch from urothelial to squamous epithelium on only morphological basis. Combination of GATA3 and Cytokeratin 14 (CK14) could be helpful in differentiating pure UC, UC with SD and pure squamous cell carcinoma (SCC). AIM: Assessment of GATA3 and CK14 expression in urinary bladder carcinoma and correlation with clinical and histopathological variables, for both diagnostic and prognostic purposes. MATERIALS AND METHODS: Sixty cases of archived paraffin blocks of urinary bladder carcinoma were tested for GATA3 and CK14 expression by immunohistochemistry using a rabbit monoclonal antibody against human CK 14 and mouse monoclonal antibody against GATA3, respectively. RESULTS: There is a significant correlation between GATA3 immunohistochemical expression and histological tumor subtypes of bladder carcinoma (p < 0.001), i.e. the GATA3 is a useful marker for urothelial origin especially in papillary UC. There is a significant correlation between GATA3 immunohistochemical expression and UC grade (p < 0.001). CK14 showed positive cytoplasmic staining in 9/14 (64.3%) cases of UC with SD and (13/13) (100%) cases of pure SCC and negative in 33/33(100%) cases of UC other than UC with SD. CK14 had sensitivity (64.3%) and specificity (100%) for areas of SD. CONCLUSION: GATA3 is a specific immunohistochemical marker for urothelial origin. CK14 is a highly specific and sensitive immunohistochemical marker of squamous cell carcinoma.