Volume 3 Article informations Expression of epithelial-mesenchymal-transition markers in breast cancer Tahani Louhichi a*, Myriam Ben Dhiab a , Sonia Ziadi a , Sarra Mestiri a , Mounir Trimeche a Abstract Aberrant expressions of proteins involved in epithelial-to-mesenchymal transition (EMT) have been described in various cancers. In this study, we sought to evaluate the expression of E-cadherin, and vimentin in breast cancer and to analyze the relationship between the expression of these markers and the stage of tumor extension. E-cadherin, and vimentin expression were investigated by immunohistochemistry in a series of 89 invasive breast carcinoma cases. We observed a decreased expression of E-cadherin in 27% of cases and an increased expression of Vimentin in 20% of cases. For clinicopathological parameters, we found that the expression of Vimentin is significantly associated with a high histological grade (p = 0.008). The expression of Vimentin by tumor cells was also significantly correlated with estrogen receptor negativity (p = 0.001), progesterone receptor negativity (p = 0.001), and triple negative tumors. However, we found no significant correlation between the expression of E-cadherin and theclinicopathological parameters studied. We also found a high prevalence of these markers in triple negative tumors (51%) compared to luminal A (2%), luminal B (9%) and HER2 (10%) (p = 0.001). Immunohistochemical analysis of the expression of E-cadherin and Vimentin allows an earlier detection of tumor progression and metastatic dissemination and leads to a better patients’ therapeutic care. Key words: Breast cancer, Epithelial-mesenchymal transition, immunohistochemistry, E-cadherin and Vimentin