Abstract: Objective:To explore the diagnostic value of detection of survivin combined with cytokeratin 19 fragments antigen,21-1 (CYFRA21-1) and carcinoembryonic antigen (CEA) in pleural effusions caused by lung cancer.Methods:Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the survivin mRNA expression in pleural effusion of 65 patients caused by lung cancer and 58 patients caused by tuberculous pleurisy,and the cytological examinations in these samples were determined.The detections of CEA and CYERA21-1 were performed by radioimmunoassay.Results:The positive rate of survivin mRNA was 80.0% in pleural effusions of lung cancer,which was significantly higher than the positive rate of initial cytological examination (47.6%).And there was no survivin mRNA expression in tuberculous pleural effusions (P<0.01).The specificity of survivin mRNA in pleural effusions caused by lung cancer (94.7%) was higher than the specificity of CEA and CYFRA21-1 (77.6% and 75.8%,respectively) (P<0.05).The sensitivity of survivin mRNA detection (80.0%) was significantly higher than CEA detection (50.8%) (P<0.05),but there was no significant difference between survivin mRNA and CYFRA21-1 detection (P>0.05).Conclusions:Survivin mRNA was a specific molecular marker for diagnosis of pleural metastasis of lung cancer,which had significant implications for diagnosis and differential diagnosis of lung cancer and tuberculous pleurisy combined with CYFRA21-1 and CEA.