Transcription Expression and Clinical Significance of TTF-1 mRNA in Pleural Effusion of Patients With Lung Cancer

The aim of this study was to evaluate diagnostic utility of thyroid transcription factor 1 (TTF-1) mRNA in pleural effusions (PEs) of patients with lung cancer, especially primary pulmonary adenocarcinoma (PPA). Transcription levels of TTF-1 were detected by reverse transcription polymerase chain reaction (RT-PCR) in PEs of patients with lung cancer (56 cases) and with lung benign diseases (44 cases). The expression rate of TTF-1 mRNA was significantly higher in PEs of patients with lung cancer (73.2%) than with benign lung diseases (0%). In subclasses, the expression rate of TTF-1 mRNA was obviously higher in PEs of patients with PPA (93.0%) than with metastatic pulmonary adenocarcnoma (0%) and with primary pulmonary squamous cell carcinoma (12.5%). When compared with immunocytochemistry and cytology, TTF-1 mRNA gave the best diagnostic performance in diagnosing PPA: sensitivity of 93.0%, specificity of 100%, and accuracy of 96.6%, respectively. As a molecular marker of detecting pleural micrometastasis, TTF-1 mRNA may be helpful to diagnose the cancer cells in PEs of patients with lung caner, especially with PPA. Diagn. Cytopathol. 2008;36:849-854. (c) 2008 Wiley-Liss, Inc.