Placental (P)-cadherin expression is associated with malignant phenotype of cancer cell. The loss of E-cadherin has been thought to play a key role in tumor progression in several cancers. In this study, we aimed to clarify the role of P-cadherin expression in non-small-cell lung cancer (NSCLC).

NSCLC patients (n = 172) were enrolled in this study; among them, 107 harbored adenocarcinomas, and 65 had squamous cell carcinomas. We examined P-cadherin and E-cadherin expression by immunohistochemical analysis and assessed the associations between each cadherin expression and both cadherin expression patterns with clinicopathological factors and prognosis. To investigate the pathway to acquire tumor progression associated with P-cadherin and E-cadherin, we examined p120 catenin localization by immunohistochemical analysis.

High P-cadherin expression was significantly associated with lymphatic metastasis, pathological stage, and Ki-67 proliferation index (P < .05, respectively). Low E-cadherin expression was significantly associated with maximum standardized uptake value, lymphatic metastasis, and pathological stage (P < .05, respectively). The cytoplasmic p120 catenin localization was associated with the low E-cadherin and high P-cadherin expression group (P < .001). High P-cadherin expression was associated with shorter disease-free survival (P = .044) and shorter overall survival (OS; P = .044). The low E-cadherin and high P-cadherin expression group was associated with shorter OS (P = .024).

High P-cadherin expression was associated with tumor progression and poor patient survival in NSCLC. In these patients, the low E-cadherin expression might be associated with tumor progression involving cytoplasmic p120 catenin.