RESUMEN
Despite the advances in diagnosis and treatment of lung cancer, its survival rate has only improved in those with early stages of disease. Telomerase is a tumor marker that has been focused on recently as a novel tool for early diagnosis of lung cancer. This study aimed to compare telomerase activity in cases with malignant and benign pleural effusions. Telomerase activity was assessed in 28 consecutive cases of pleural effusions [19 cases with malignant and 9 cases with benign histopathologic diagnosis] with telomeric repeat amplification protocol [TRAP] between Apr. 2006 and Sep. 2007. Data analysis was performed by using Chi-square test and t-test. Twenty [71.4%] out of 28 cases with pleural effusions were positive for telomerase activity. Telomerase activity was positive in all 19 malignant effusions, while only one case with effusion due to a benign condition [TB] had positive telomerase activity [p < 0.0001]. The sensitivity, specificity and diagnostic accuracy of telomerase activity for detecting malignant pleural effusions were 100%, 88.9% and 96.4%, respectively. Positive and negative predictive values of telomerase activity were 95% and 100%, respectively. Mean relative telomerase activity was not significantly different in malignant and benign effusions [24.3 +/- 5.2% vs. 15.05%; p>0.05] 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 cytology for malignant pleural effusions