Comparison of telomerase activity in malignant and benign pleural effusions

Background: Despite advances in diagnosis and treatment of lung cancer, patients survival has just improved in those with early stages. Telomerase is a tumor marker that has been focused recently as a novel tool for early diagnosis of lung cancer. Objective: To compare telomerase activity in malignant and benign pleural effusions in Rasoul-e-Akram Hospital of Tehran. Methods & materials: Telomerase activity in 28 consecutive pleural effusions (19 malignant and 9 benign; histopathologic diagnosis) assessed with telomeric repeat amplification protocol (TRAP) between Apr. 2006 and Sep. 2007. Data analysis was performed by chi-squared test and t-test; results expressed as frequency, percent, and mean ± SD. Result: 20 cases (71.4%) from the total of 28 pleural effusions were positive for telomerase activity. Telomerase activity was positive in all 19 malignant effusions, while only one effusions from benign conditions (TB) had telomerase activity (P<0.0001). Sensitivity, specificity and diagnostic accuracy of telomerase activity for detecting malignant pleural effusions were 100%, 88.9% and 96.4% respectively. Mean telomerase relative activity in malignant and benign effusions was not significantly different (24.3±5.2% vs. 15.05%; P>0.05). Conclusion: Telomerase activity is a highly sensitive and specific diagnostic biomarker for malignancy and may be used as an adjunct to other diagnostic tools such as cytological findings for malignant pleural effusions.