Recently, TSLC1 (tumor suppressor in lung cancer 1) gene has been identified as a novel tumor suppressor in human non-small cell lung cancers. The clinical relevance of TSLC1 gene expression has never been studied using patients’ data and surgical samples. The present study was designed to evaluate whether the TSLC1 gene can be serve a target for a prognostic determinant of patients with pulmonary adenocarcinomas.
A total of 38 patients surgically treated for proven primary lung adenocarcinoma, were enrolled in this study. Surgical specimens were examined for TSLC1 protein expression immunohistochemically and by Western blot analysis. The correlation between levels of TSLC1 expression and pathologic characteristics as well as prognosis was investigated.
All the patients were subjected to a potentially curative resection of the tumor. TSLC1 antigen expression evaluated by immunohistochemistry was confirmed by immunoblotting. The expression of TSLC1 protein correlated inversely with advanced stage, nodal involvement, lymphatic permeation and vascular invasion. The 4-year overall survival rates of patients with a tumor showing a high (>70% positive cells, n=14), intermediate (20%-70%, n=10), and low (<20%, n=14) expression of the TSLC1 antigen were 84%, 28%, and 7%, respectively. The disease-free survival, in addition to overall survival, of patients with a tumor showing a high percentage of TSLC1 protein-positive cells was significantly better than that of patients with a tumor showing a low percentage of TSLC1 protein-positive cells.CONCLUSIONS: The loss or reduction of TSLC1 expression in resected lung adenocarcinomas was associated with a poor prognosis, indicating that the TSLC1 represents a central effector gene for controlling the biological aggressiveness of the tumor and that it is an essential biomarker for predicting the patient’s prognosis.
These data may help to detect patients at a high-risk of recurrence who could benefit from additional therapeutic strategies such as adjuvant therapy.
M. Okada, None.