Background: Preservation of E-cadherin expression is usually related to non-invasive and well differentiated breast carcinomas.
Purpose: The aim of this study was to evaluate E-cadherin immunohistochemical expression in estrogen receptor (ER) positive and negative infiltrating ductal breast carcinomas.
Methods: Twenty-three postmenopausal patients with Stage II, operable, infiltrating ductal breast carcinomas were divided into groups A (ER+; n = 13) and B (ER-; n = 10). E-cadherin immunohistochemical expression was assessed semiquantitatively according to membrane staining intensity and classified as negative (< 10% of cells with stained membranes), positive + (10-50% of cells stained) or positive ++ (> 50% of cells stained). Fisher's exact test was used to compare the distribution of staining intensity in the two groups (p < 0.05).
Results: In group A (ER+), E-cadherin staining was positive in all cases: + (n = 3; 23%) and ++ (n = 10; 77%) compared to three cases (30%) in group B (ER-), + (n = 2; 20%) and ++ (n = 1; 10%). This difference was statistically significant (p < 0.0005).
Conclusions: The present results indicate that E-cadherin expression loss is significantly associated with ER-negative tumors and therefore with a more aggressive phenotype of invasive ductal breast carcinoma.