Serum and Bronchoalveolar Lavage Fluid Levels of Cytokines in Patients with Lung Cancer and Chronic Lung Disease: A Prospective Comparative Study

The role of chronic inflammation in the initiation and progression of carcinogenesis has been well-established in previous studies, particularly in the stages of malignant conversion, invasion, and metastasis. This study aimed to explore the potential correlation between the levels of cytokines in serum and bronchoalveolar lavage fluid (BALF) by comparing their levels between patients with lung cancer and those with benign lung diseases. The study measured the concentration of IFN-γ, TNF-α, IL-1β, IL-2, IL-4, IL-6, IL-10, and IL-12p70, in venous blood and BALF of a total of 33 patients with lung cancer and 33 patients with benign lung diseases. Significant differences were found between the two groups in various clinical parameters. The cytokine levels were significantly higher among patients with malignant disease, while the BALF analysis revealed higher cytokine levels compared with serum analysis. It was discovered that the levels of cancer-specific cytokines in the lavage fluid increased significantly sooner and were present at a greater concentration than those in the peripheral blood. After one month of treatment, the serum markers decreased significantly but slower in the lavage fluid. The differences between serum and BALF markers remained significant. It was observed that the highest correlation was among IL-6 (serum) and IL-6 (lavage), with a coefficient of 0.774 (p-value < 0.001), and IL-1 (serum) and IL-1β (lavage), with a coefficient value of 0.610 (p-value < 0.001). Other significant correlations among serum and lavage cytokines were observed between IL-6 (lavage) and IL-1 (serum) (rho = 0.631, p-value < 0.001) and CRP (rho = 0.428, p-value = 0.001), respectively. This study revealed significant differences and correlations in clinical parameters, serum markers, and BALF inflammatory markers between patients with lung cancer and those with benign lung pathologies. The results highlight the importance of understanding the inflammatory profiles of these conditions and could contribute to the development of targeted therapies or diagnostic approaches in the future. Further research is needed to validate these findings, explore their implications for clinical practice, and determine the diagnostic and prognostic value of these cytokines for lung cancer.