Luminal Versus Non-luminal Breast Cancer CDH1 Immunohistochemical Expression

We investigated the immunohistochemical expression of E-cadherin (product of CDH1 gene) and its correlation with clinical-pathological parameters and survival rate in the molecular groups of breast cancer. Our study included female breast cancer patients diagnosed at the Municipal Emergency Clinical Hospital Timisoara followed up five years since diagnosis using formalin fixed paraffin embedded tissue. The traditional prognostic factors (age, tumor size, histological type, histological grade, anatomical status of the lymph nodes) were abstracted from histopathology reports and we set prognostic index (the Nothingham and lymph-node prognosis index). Molecular classification on selected cases was performed in agreement with data from the literature: luminal A, B, HER2+, triple-negative. We noted positive (membranar) expressions in 43 cases (70.49 %). Negative immunoreactions for E-cadherin have been observed in all cases of lobular carcinomas (4 cases), as well as 6 cases of mixed carcinomas. A significant correlation was found between E-cadherin expression and hormonal status, tumor size, histologic type, tumor grade and molecular subtype. Most of the luminal A and B tumors were E-cadherin positive, while more than half of non-luminal tumors were E-cadherin negative. Survival rates are different in the negative and positive E-cadherin tumor groups respectively and between luminal and non-luminal groups. E-cadherin expression may be a useful prognostic marker for classifying other subgroups of breast cancer.