E-cadherin (E-cad) expression in duct carcinoma in situ (DCIS) of the breast

E-cadherin (E-cad) is an epithelial cell-cell adhesion molecule whose loss or reduced expression is associated with a more invasive tumour phenotype. Ninety-six cases of screen detected pure ductal carcinoma in situ (DCIS) were analysed immunocytochemically for expression of E-cad using the HECD-1 mouse monoclonal antibody. The in situ component in each case was classified on the basis of cytonuclear grade, extent of necrosis, Van Nuys classification and a newly devised Cardiff classification. The amount of E-cad expression was assessed semi-quantitatively using an intensity distribution method. There is significantly more expression of E-cad in well-differentiated DCIS when compared with poorly differentiated DCIS and this finding is highly significant (P<0.001) irrespective of the classification system used. These findings suggest that progressive loss of E-cad expression may occur at an early stage of breast cancer development.