Expression of E-cadherin/catenin complexes in breast cancer: correlation with favourable prognostic factors and survival

Expression of E-cadherin, alpha-, beta- and gamma-catenins were studied in 100 patients with primary breast cancer compiled of 57 invasive ductal carcinomas (IDC) and 43 invasive lobular carcinomas (ILC) by means of immunohistochemistry. Loss of E-cadherin was observed in 26 (45.6%), and alpha-, beta- and gamma-catenin expression was lacking in 22 (38.6%), 27 (47.4%) and 22 (38.6%) IDCs, respectively. The expression in ILCs was significantly lower, as compared to IDCs (p<0.001). Immunostaining of both E-cadherin and catenins was completely lacking in 27 (47.4%) IDCs and 30 (93.8%) ILCs. Go-expression of E-cadherin/beta-catenin or E-cadherin/gamma-catenin was preserved more frequently than that of E-cadherin/alpha-catenin complexes. E-cadherin/catenin complex expression showed significant positive correlation with histological differentiation (p=0.037), ER (p=0.017) and PR expression (p=0.052), and negative correlation with c-erbB-2 receptor overexpression (p=0.046). Patients with tumours showing adhesion complexes containing alpha-catenin had an increased overall survival rate compared to other patients. Expression of either E-cadherin or alpha-catenin only, without the formation of entire adhesion complexes, was not correlated with overall survival. Thus, determination of both E-cadherin and catenins is suggested to add further information to estimate the prognosis of breast cancer patients.