Role of cancer ratio and other new parameters in the differential diagnosis of malignant pleural effusion

Abstract

OBJECTIVES: We compared the diagnostic potential of cancer ratio (CR, serum lactate dehydrogenase [LDH]/ pleural fluid adenosine deaminase [pfADA]), cancer ratio plus (CR plus, cancer ratio/pleural lymphocyte percentage), and age/pfADA ratio with pfADA in malignant pleural effusion. METHODS: Data from 100 patients with malignant pleural effusion (MPE) and 119 patients with tuberculous pleural effusion (TPE) were retrospectively collected. PfADA, age/pfADA ratio, CR, and CR plus were compared between patients with MPE and those with TPE in two age groups (p50 and 450 years). The best cut-off value was determined, and the diagnostic performance was evaluated according to the receiver operating characteristic curve. RESULTS: PfADA was statistically significantly lower while age/pfADA ratio, CR, and CR plus were significantly higher in the MPE group than in the TPE group in both age groups (po0.05). For patients aged p50 years, the differential diagnostic value of pfADA for MPE was better than those of age/pfADA ratio, CR, and CR plus. At a cut-off value of 13.0 U/L, the sensitivity, specificity, and accuracy were 88.9%, 100.0%, and 98.9%, respectively. For patients aged 450 years, the diagnostic performance of CR plus was superior to those of pfADA, age/pfADA ratio, and CR. At a cut-off value of 22.6, the sensitivity, specificity, and accuracy of CR plus for the diagnosis of MPE were 86.8%, 84.6%, and 86.2%, respectively. CONCLUSIONS: The best parameter for diagnosing MPE was different for patients aged p50 years and 450 years. For patients aged 450 years, CR plus was a good parameter for the differential diagnosis of MPE. For patients aged p50 years, pfADA was better.