Prognostic significance of pleural fluid data in patients with malignant effusion

Abstract

Background: To determine the effects of the biochemical and cytological properties of the pleural fluid (PF) on the survival of patients with malignant pleural effusion (MPE).

Methods: A retrospective study of 284 patients with MPE was performed, which measured overall survival, survival of patients with different types of primary tumors, and survival as a function of PF biochemical variables transformed into quartiles.

Results: Median overall survival of MPE patients was 5.4 months following diagnosis. Survival varied significantly depending on the type of the primary tumor: 17.4 months for mesothelioma, 13.2 months for breast cancer, 7 months for lymphoma and 2.6 months for lung cancer. A multivariate analysis of PF biochemical parameters showed that survival was lower as the concentration of lactate dehydrogenase (LDH) increased (11.3 months if LDH was between 140 U/L and 358 U/L vs 2.8 months if LDH was between 1027 U/L and 10,110 U/L) or the concentration of pleural proteins decreased (9.4 months if proteins were between 4.92 g/dL and 7.94 g/dL vs 2.2 months if proteins were between 0.97 g/dL and 3.85 g/dL). We also found that when mesotheliomas were excluded from the analysis, survival was lower in patients with a PF pH lower than 7.3 (2.4 months vs 6.8 months, p=0.03).

Conclusions: Tumor type as well as some biochemical features of the pleural fluid, such as pH and concentrations of proteins and LDH, influence survival in patients with MPE.