Study of telomerase activity in pleural lavage fluid specimens in patients with non-small-cell lung cancer and its clinical significance

Objective: To detect telomerase activity in pleural lavage fluid specimens in patients with non-small-cell lung cancer (NSCLC) and to evaluate its clinical value. Methods: From July 2005 to May 2007, 167 pleural lavage fluid specimens were obtained from 135 patients with NSCLC and 32 patients with benign lung tumour during operation. Telomeric repeated amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA) was performed to measure the telomerase activity in these specimens. Pleural lavage cytology (PLC) analysis of the pleural lavage fluid specimens was used for comparison. All the above specimens were examined within 3 h. Results: The positive rate of telomerase activity and PLC in pleural lavage fluid from patients with NSCLC was 25.2% (34/135) and 8.1% (11/135), respectively, with a significant difference (P < 0.05). Telomerase activity was detected in all 11 specimens with positive cytological examination. Telomerase activity was negative in all 32 patients with benign lung tumour. There was a significant relationship between telomerase activity and pleural extension, T level, N level as well as the clinical TNM (tumour, node, metastasis) stage of lung cancer. A significant association was found between positive telomerase activity and overall survival rate, even stage I survival rate. Multivariate Cox regression analysis demonstrated that telomerase activity, as well as PLC and the TNM stage were independent predictors of prognosis. Conclusion: Telomerase activity is a useful adjunct for cytological method in the diagnosis of pleural micro-metastasis and was related to prognosis in a patient with NSCLC.