Evaluation of serum cyfra21 in patients with pleural effusion

Background: The aim of this study is to determine the level of serum cytokeratin19 fragment (cyfra21-1) in patients with benign or malignant pleural effusion and evaluation the sensitivity and specificity of this tumor marker. Method & Material: We prospectively evaluated 98 patients (39 malignant, 54 benign and the results were inconclusive in 5) with pleural effusion. The diagnosis of malignant pleural effusion was defined by cytological or histological results. We used serum cyfra21-1 criteria from literature of Roch company. Level of the marker was determined using electrochemiluminescence. Results: There was statistically significant difference between mean of serum cyfra21-1 levels of benign (3.9±7.6) and malignant(19.5± 30) pleural effusion (p=0.01). In addition the sensitivity, specificity, positive predictive value and negative predictive value of serum cyfra21-1 at the cut off point of 3.3 ng/ml , was 84% , 61%, 61% and 84 % respectively. Conclusion: Serum cyfra21-1 is useful as a measure in differentiating malignant from benign pleural effusion.