Objective: Some histological basal cell carcinoma (BCC) types demonstrate more aggressive behavior than others. They are known as high-risk BCC and are more challenging in therapy, contrary to indolent (low-risk) BCC types. Identifying novel protein markers to predict aggressiveness and potential therapeutic targets in challenging cases is recommended. GATA3 is a transcription factor critical for epithelial and lymphocytic differentiation. This study investigated the immunohistochemical expression of GATA3 in indolent and aggressive BCC and its association with BCL2 expression.

Material and Methods: Retrospectively collected indolent and aggressive BCC groups (24 cases each) were immunohistochemically stained with anti-GATA3 and BCL2 antibodies. The mean expression score (by area percentage) and TIL counts were determined and compared using ImageJ analysis. Stromal tumor-infiltrating lymphocytes (TIL) were counted per high-power field (HPF) on hematoxylin and eosin (H&E) staining.

Results: GATA3 and BCL2 expressions were significantly higher in the indolent group than in the aggressive group. GATA3 expression significantly correlated with BCL2 score and TIL counts. Higher GATA3 expression was significantly associated with a more indolent BCC histological type, higher BCL2 expression, and higher TIL count.

Conclusion: GATA3 is a possible target for immunomodulation experiments to improve BCC immunotherapy outcomes.