Evaluation of GATA3 and HER-2 Immunohistochemical Expression as Prognostic Markers in Urothelial Carcinoma of the Urinary Bladder.

Objective

Urothelial carcinoma (UC) of the bladder remains a significant clinical challenge due to its high rates of recurrence and progression. Reliable biomarkers to predict tumor behaviour are still needed. GATA3 and HER2 have gained attention in this context, but their combined prognostic value has not been fully established. This study aims to evaluate the immunohistochemical expression of GATA3 and HER2 in bladder UC and to examine their association with key pathological parameters and patient outcomes.

Methods

One hundred archival UC specimens (2018-2022) were reviewed. Immunohistochemical staining for GATA3 and HER2 was performed and scored using a semi-quantitative H-score. Clinicopathological data and 3-year follow-up information were analysed to assess correlations with recurrence, progression, and survival.

Results

GATA3 expression was detected in 80% of tumors, while HER2 was positive in 25%. Both markers were significantly associated with low-grade histology and non-muscle-invasive disease. Tumors co-expressing GATA3 and HER2 showed the most favorable outcomes, including lower recurrence and improved 3-year disease-free survival. In multivariate analysis, GATA3 retained independent prognostic significance (HR 0.45, p=0.006). HER2 demonstrated a favorable trend that did not reach statistical significance after adjustment for grade and stage (HR 0.60, p=0.12), suggesting its prognostic signal is partially mediated by tumor differentiation.

Conclusion

In multivariate analysis, GATA3 retained independent prognostic significance (HR 0.45, 95% CI 0.25-0.80, p=0.006), while HER2 did not (HR 0.60, 95% CI 0.35-1.03, p=0.12). However, combined GATA3/HER2 positivity identified a luminal subgroup with significantly better outcomes, supporting the utility of this marker panel for prognostic stratification in early-stage bladder UC.