Abnormal α-catenin expression in invasive breast cancer correlates with poor patient survival Aims: α-Catenin is a member of the E-cadherin-catenin family of adhesion molecules whose role is essential for the function of the E-cadherin complex. In this study, we have evaluated the expression of α-catenin but also of the other catenins (β-, γ- and p120-catenin) and E-cadherin in invasive breast cancer and statistically analysed these expressions with known clinicopathological parameters, c-erbB-2 oncoprotein expression and patient survival. Methods and results: Abnormal E-cadherin and β-catenin expression, especially loss of expression, was associated with lobular histological type of breast carcinomas (P =0.03 and P =0.01, respectively). Abnormal E-cadherin and α-catenin expression was associated with high histological grade ductal carcinomas (P =0.01 and P =0.03, respectively). Abnormal E-cadherin and β-catenin expression was correlated with lymph node metastases (P =0.02 and P =0.05, respectively), while abnormal α- and β-catenin were correlated with the advanced stage of the disease (P =0.04 and P =0.05, respectively). Abnormal p120-catenin expression was associated with loss of PR (P =0.008). Survival analysis demonstrated a statistically significant association between abnormal α-catenin expression and poor patient survival (P =0.02). When survival analysis was performed according to the different patterns of abnormal expression, statistically significant associations were seen between cytoplasmic α- and β-catenin expression and poor survival (P =0.006 and P =0.04, respectively). Conclusions: α-Catenin, especially its cytoplasmic expression, seems to be a more sensitive prognostic marker than the other members of the E-cadherin complex in invasive breast cancer. [ABSTRACT FROM AUTHOR]