Expression of E-cadherin and beta-catenin in human non-small cell lung cancer and the clinical significance.

E-cadherin, a calcium-dependent cell-cell adhesion molecule, plays a key role in the maintenance of tissue integrity. The function of this molecule is partly mediated by alpha-/beta-/gamma-catenin. Loss or dysfunction of E-cadherin is associated with an invasive phenotype. We analyzed the expression of E-cadherin and beta-catenin in human lung cancer to determine the relationship to clinicopathological factors and prognosis. E-cadherin and beta-catenin expressions were evaluated in 331 lung cancer tissues in a immunohistochemical analysis. Reduced E-cadherin expression was evident in 138 (42%), and reduced beta-catenin expression was noted in 122 (37%). Reduced E-cadherin expression significantly correlated with lymph nodes metastasis (P = 0.0199). E-cadherin expression significantly correlated with increasing histological differentiation (P = 0.0403). Although reduced E-cadherin did not correlate with the prognosis (P = 0.0652), reduced beta-catenin expression did significantly correlate with a poor prognosis (P = 0.0001). When both were reduced, there was a significant unfavorable prognosis compared with either the reduced expression (P = 0.0493) and preserved expression (P = 0.0003). Multivariate analysis showed a significantly lower survival rate for patients with reduced beta-catenin (P < 0.0001). We interpret these data to mean that dysfunction of the cell-cell adhesion molecule has a role in the progression of lung cancer and that analysis of E-cadherin and beta-catenin expression can provide clinically important evidence on which to base treatment.