Abstract

Utility of ferritin (FR) levels in the differentiation of exudative malignant and benign pleural effusions was investigated in 51 consecutive patients in a prospective study. Pleural FR levels were 1417±939 ng/ml in 36 patients with exudative benign pleural effusion, and 1604±884 ng/ml in 15 patients with malignant effusion (p=0.08) while serum FR levels were 345+326 and 323+260 ng/ml (p=0.11), respectively. Of the serum and pleural protein, albumin, amylase, cholesterol, glucose and lactate dehydrogenase levels, only serum and pleural lactate dehydrogenase, and pleural protein levels showed significant difference between malignant and benign cases (p<0.05). Pleural or serum FR levels were not significantly correlated with any of the other parameters measured (p>0.05, r= -0.09 – +0.10) or wtih the performance status of the patients (p>0.05, r= -0.07 – +0.12). When a cut-off value of 1500 ng/ml was taken for pleural FR level, specificity, sensitivity, positive and negative predictive values were 60, 65, 40 and 78% respectively; while they were 93, 13, 29 and 100% respectively when the cut-off value was taken as 500 ng/ml. Pleural/serum FR ratio was deter - mined as 5/1 in malignant, and 4/1 in benign pleural effusions (p>0.05). It was concluded that pleural FR level and pleural/serum FR ratio are not useful in differentiating malignant and benign exudative pleural effu - sions, and therefore cannot be used as tumor markers.