E-cadherin expression in molecular types of breast carcinoma.

E-cadherins are epithelial morphological stabilizers, performing complex functions as receptors, providers of cellular and tissular structural integrity, and functional interactive mediators. Structural and functional unbalance initiated due to E-cadherin expression loss results in direct effects on carcinogenesis specific biological processes, as cellular invasion and proliferation. We investigated the E-cadherin expression aiming (i) to identify the differences in the molecular subtypes of breast cancer, (ii) to analyze the correlations between E-cadherin and specific clinicopathological and molecular characteristics. The study included 42 cases that were investigated immunohistochemically using a panel of antibodies (ER, PR, Her2/neu, CK5/6, EGFR), which permitted a diagnostic in compliance with the molecular classification, followed by the E-cadherin evaluation. The semi-quantitative assessment of E-cadherin was performed using a scoring system based on the positive cells percentage and the staining intensity. Our results showed, according to the molecular subtypes, a strong positive E-cadherin expression in 26 cases (luminal A subtype - nine cases, luminal B subtype - five cases, HER2 subtype - three cases, basal-like subtype - seven cases, unclassified subtype - two cases), and a weak positive one in 16 cases (luminal A subtype - six cases, luminal B subtype - eight cases, HER2 subtype - one case, basal-like subtype - one case). The statistical analysis revealed significantly statistical differences between E-cadherin and tumoral grade (p=0.0208), histological subtype (p=0.0081), triple negative molecular subtypes and non-triple negative, respectively (p=0.0361). These findings support the potential value of E-cadherin for a supplementary differentiation of molecular subtypes, based on the biological significance of its capacity of expression.