Potential role of BRCA1 protein expression as a prognostic tissue biomarker in breast carcinoma: an immunohistochemical and clinicopathologic study from South India

Introduction. BRCA1 dysfunction is a hallmark of both hereditary and sporadic breast cancer. BRCA1 protein expression can be lost by germline mutation, somatic mutation or promoter hypermethylation. This study aimed to explore BRCA1 dysfunction in breast cancer patients by immunohistochemistry and to study its association with prognostic factors. Material and methods. BRCA1 protein expression was assessed by immunohistochemistry on formalin fixed paraffin embedded tissue blocks of 110 invasive breast carcinoma patients. Furthermore, the clinical findings and tumor features associated with BRCA1 dysfunction were characterized. Results. Reduced BRCA1 immunoreactivity was observed in 19% of breast cancer cases. Although these patients presented with aggressive tumor characteristics, statistical significance was observed only with presence of lymphovascular emboli (p < 0.05). These results suggest that loss of BRCA1 protein expression is associated with an aggressive phenotype of breast carcinoma. Conclusions. Immunohistochemistry for BRCA1 protein expression in tumor tissues may provide a less expensive screening tool to identify BRCA1 dysfunction due to genetic or epigenetic alterations