Clinical significance of epithelial-mesenchymal transition-related molecules in lung adenocarcinoma

Background Epithelial-mesenchymal transition (EMT) refers to the biologic process in which epithelial cells are transformed into interstitial phenotypes by specific pathways. This transition plays an important biologic role in the process by which epithelium-derived malignant tumour cells acquire the ability to migrate and invade. We explored the relationship between EMT-associated molecules and patient-related clinical factors to determine whether any clinical characteristics could be used as biomarkers for EMT-related protein alterations in lung cancer-especially lung adenocarcinoma. Methods Tumour specimens were collected from 80 patients with lung adenocarcinoma who underwent surgery or lung biopsy, with 4 patients being evaluated a 2nd time after re-biopsy. Expression of EMT-related proteins, including E-cadherin and vimentin, was evaluated by immunohistochemistry. We analyzed the relationship between clinicopathologic characteristics and expression level of the EMT markers. Results Positive expression of E-cadherin was observed in 63 patients (79%), and vimentin, in 46 patients (57.5%). No significant relationships between E-cadherin or vimentin expression and smoking history, sex, age, driving gene mutations, or cell differentiation were identified. A significant correlation was observed between vimentin expression and pathologic stage. Of the 4 patients who were evaluated a 2nd time after re-biopsy, 3 showed the same EMT-related protein expression status as in the first analysis. In the remaining patient, E-cadherin had changed completely. Conclusions Clinicopathologic factors in cancer patients did not help to diagnose EMT status in lung adenocarcinoma; however, TNM stage might be associated with vimentin expression.