Expression of E-cadherin in human ductal breast cancer carcinoma in situ, invasive carcinomas, their lymph node metastases, their distant metastases, carcinomas with recurrence and in recurrence

Background: Breast cancer cells can invade and generate metastasis via either lymphatic or blood vessels. E-cadherin mediates tumor cell-cell adhesion. Partial or complete loss of E-cadherin expression correlates with poor prognosis in breast cancer patients. In this study, the expression of E-cadherin was examined in mammary ductal carcinoma in situ, invasive breast carcinomas without metastasis, invasive carcinomas with their lymph node and distant metastases and invasive carcinomas with local recurrence in breast cancer tissue. Materials and Methods: Paraffin-embedded slides of carcinoma in situ (8 DCIS), invasive carcinomas without lymph node metastases (9 invasive ductal carcinomas), invasive carcinomas (7 invasive ductal carcinomas) with corresponding lymph node metastases, invasive carcinomas (8 invasive ductal carcinomas) with corresponding recurrence and invasive carcinomas (5 invasive ductal carcinomas) with corresponding distant metastases were investigated for E-cadherin expression. Tissue slides were incubated with monoclonal antibodies against E-cadherin and stained with the ABC-elite kit. Staining intensities were analyzed by using a semi-quantitative score. Results: A strong expression of E-cadherin in carcinoma in situ was demonstrated. Expression of E-cadherin was moderate in invasive carcinomas without metastases. However, very weak expression of E-cadherin in primary carcinoma with lymph node metastases was detected. E-cadherin expression was elevated in lymph node metastases compared to the primary tumor. Conclusion: Analysis of a tumor antigen involved in adhesion of breast cancer cells showed that there are significant differences of expression of E-cadherin between primary breast cancer cells and their metastases. Evaluation of this marker involved in cell adhesion could be a useful method for evaluating the metastatic risk in breast cancer patients.