In breast carcinoma dysadherin expression is correlated with invasiveness but not with E-cadherin.

Reduction/loss of E-cadherin is associated with the development and progression of many epithelial tumours. Dysadherin, recently characterised by members of our research team, has an anti-cell-cell adhesion function and downregulates E-cadherin in a post-transcriptional manner. The aim of the present study was to study the role of dysadherin in breast cancer progression, in association with the E-cadherin expression and the histological type. We have selected ductal carcinoma, which is by far the most common type and lobular carcinoma, which has a distinctive microscopic appearance. Dysadherin and E-cadherin expression was examined immunohistochemically in 70 invasive ductal carcinomas, no special type (NST), and 30 invasive lobular carcinomas, with their adjacent in situ components. In ductal as well as in lobular carcinoma dysadherin was expressed only in the invasive and not in the in situ component, and this expression was independent of the E-cadherin expression. Specifically, all 10 (100%) Grade 1, 37 out of 45(82.2%) Grade 2 and six out of 15 (40%) Grade 3 invasive ductal carcinomas showed preserved E-cadherin expression, while 'positive dysadherin expression' was found in six out of 10 (60%) Grade 1, 34 out of 45(75.5%) Grade 2 and all 15 (100%) Grade 3 neoplasms. None of the 30 infiltrating lobular carcinomas showed preserved E-cadherin expression, while all the 30 infiltrating lobular carcinomas exhibited 'positive dysadherin expression'. Dysadherin may play an important role in breast cancer progression by promoting invasion and, particularly in lobular carcinomas, it might also be used as a marker of invasion.