Expression of TRPS1, WNT9B, GATA3 and SOX10 markers in Primary triple negative breast carcinomas

Background: Triple-negative breast carcinoma (TNBC) is an aggressive subtype of breast cancer, characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and HER2 expression. Because TNBC has a variety of histopathological presentations and adverse clinical behaviour, it is important to find sensitive and specific markers to help with diagnosis and characterisation that helps in treatment of TNBC. In order to determine the diagnostic utility of TRPS1, WNT9B, GATA3, and SOX10 markers, this study analyses their immunohistochemical (IHC) expression patterns in primary TNBC cases. Methods: The study included 30 histologically and immunohistochemically confirmed cases of primary TNBC. IHC staining for TRPS1, WNT9B, GATA3, and SOX10 was performed on formalin-fixed, paraffin-embedded tumor sections.Additionally, the Ki67 proliferation index was evaluated. Staining intensity and the proportion of positive tumour cells were used to classify expression. Results: TRPS1 expression was observed in 73.3% of cases, highlighting its potential utility as a diagnostic marker in TNBC. WNT9B showed positivity in 56.6% of tumors, while GATA3, typically associated with luminal subtypes, was positive in 46.6% of cases, indicating that a subset of TNBC retains features of luminal differentiation. SOX10, which is known to play a part in both basal and myoepithelial differentiation, tested positive in 76.6% of the cases, indicating that it is important for detecting basal-like TNBC. The cohort's variable proliferative activity was reflected in the Ki67 labelling index, which had a mean of 26.2% and ranged from 10% to 70%. Conclusion: The combined expression of TRPS1 and SOX10 provides valuable diagnostic assistance in the characterization of TNBC. While GATA3 positivity suggests heterogeneous differentiation patterns, WNT9B emerges as a significant marker of further investigation in the TNBC subset. Incorporating these markers in diagnostic panels may improve diagnostic accuracy and guide personalized management strategies.