Angiopoietin 2 levels in serum and bronchial lavage fluids and their relationship with cancer stages in lung cancer patients

Background: Angiopoietin 2 (Ang‐2) has an important role in tumor angiogenesis. In this study, Ang‐2 levels of serum and bronchioloalveolar lavage fluids (BALF) in patients with lung cancer were measured and correlated with clinical and biochemical parameters. Methods: Thirty‐five cases newly diagnosed with lung cancer and 18 controls with non‐cancerous lung diseases were included in the study. Tumor histology, staging, metastasis, tumor markers, biochemical and clinical parameters were all recorded. Results: Serum Ang‐2 levels were significantly higher in the lung cancer group compared to the control (lung cancer median: 2.42 ng/mL [2.19–2.98], control 0.67 [0.31–1.10]; P < 0.001), whereas Ang‐2 levels in BALF were lower in the lung cancer group compared to the control (lung cancer median 0.41 ng/mL [0.22–0.79], control 0.67 [0.46–1.03]; P = 0.02). In the cancer group, higher serum Ang‐2 levels (r = 0.52, P < 0.001) were associated with the stage of cancer. No significant correlation was observed between BALF Ang‐2 levels and non‐small cell lung cancer stages and small‐cell lung cancer advanced stage (P = 0.793, r = 0.07). Serum Ang‐2 levels were significantly higher in distant metastasis (M1) versus no distant metastasis (M0) (M1: 2.57 ng/mL [2.38–2.87], M0: 2.22 [1.49–2.40], P = 0.01). No significant correlation was observed between BALF Ang‐2 levels and M1 (r = 0.11, P = 0.53). Conclusions: Serum Ang‐2 levels were significantly higher in lung cancer patients and positive correlations were observed between serum Ang‐2, tumor stage, and metastasis.