Objective: Malignant pleural effusions (MPEs) deteriorate the quality of life in patients with advanced stages of cancer. Although vascular endothelial growth factor (VEGF) is known to be a key factor for MPE formation, it is not fully clarified whether there are other components related to its appearance.
Methods: Pleural effusion and serum samples were collected from patients with MPEs of non-small cell lung cancer. Cellular analysis of pleural effusion was performed using fluorescence flow cytometry. The concentrations of 12 cytokines, chemokines, and growth factors in MPEs and serum samples were analyzed using the cytometric bead array method.
Results: Fifteen patients (median age: 70 years, 11 males) with non-small cell lung cancer (13 adenocarcinoma, 2 squamous cell carcinoma) were enrolled in this study. Concentrations of VEGF, interleukin (IL)-5, IL-6, IL-8, IL-12/IL-23p40, and C-C motif chemokine ligand (CCL) 2 were significantly higher in MPE than in serum. Pleural IL-5 levels correlated with malignant cell numbers in MPE. There was no factor related to the total amount of drained effusion or period of chest tube insertion.
Conclusions: Production of six molecules were increased in the pleural cavity with MPE of non-small cell lung cancer. Complex interactions among these molecules may regulate MPE formation.