May Biochemical Variables and Pleural Fluid Cell Count Be Used in the Benign- Malign Differentiation of Pleural Effusions Associated with Lung Cancer?

Abstract

Objective:Pleural effusion is frequently encountered in patients with lung cancer. Malignant-benign differentiation of the fluid is very important for treatment decision because malignant fluid is considered as the inoperability criterion. However, this distinction is not clinically feasible and may require a cytological examination of the fluid via invasive procedures. The aim of this study was to determine whether there was any difference between laboratory results of malignant and benign pleural fluids.Methods:We retrospectively evaluated 135 patients with cytologically diagnosed lung cancer and underwent benign-malignant differentiation of pleural effusion. Benign and malignant groups were compared in terms of fluid biochemistry, blood gas and cell count.Results:One hundred four patients were male, 31 were female and the mean age was 63.5±11.4 years. Histologically adenocarcinoma was determined as the most common (56%). Right pleural effusion was present in 58.5% of the patients. Malignant effusion rate was higher in females (malign/benign; female: 21/10, male: 48/56). Albumin, protein, erythrocyte count (RBC) and hematocrit (HCT) values in pleural fluid were higher in the malignant group (p=0.001, p=0.018, p=0.009 and, p=0.016, respectively). Cut-off value for albumin: 2.85 and odds ratio (OR): 2.02; for HCT 4.7 and OR: 6.25; for RBC 300 and OR: 6.25; for protein 4.45 and OR: 2.08.Conclusion:In our study, we found that the values of albumin, HCT, RBC and protein in pleural fluid were higher in malignant pleural effusion.

Keywords

• Pleural effusion
• lung cancer
• fluid biochemistry