Preoperative serum oxidative stress marker as a strong indicator of nodal involvement in clinical stage I lung adenocarcinoma.

BACKGROUND: Reactive oxygen species stimulate lymphatic metastasis by accelerating epithelial-to-mesenchymal transition and lymphangiogenesis in the tumor microenvironment. Hence, systemic oxidative stress level may correlate with nodal involvement in patients with a malignant tumor.
METHODS: We examined 46 patients with clinical stage I lung adenocarcinoma who had undergone pulmonary resection with mediastinal lymph node dissection. Serum reactive oxygen metabolite (ROM) level was measured as an indicator of systemic oxidative stress. We investigated the association between nodal involvement and clinicopathological factors.
RESULTS: Preoperative serum carcinoembryonic antigen (CEA; P = 0.045), cytokeratin 19 fragment (CYFRA21-1; P = 0.038), and ROM (P = 0.007) levels were significantly higher in patients with nodal involvement than in those without nodal involvement. A receiver operating characteristic curve was constructed to determine whether patients with and without nodal involvement could be differentiated on the basis of their serum ROM levels. The area under curve was 0.763 and the prognostic cut-off value was set at 318 Carratelli units. In univariate analysis, clinical stage IB (odds ratio [OR] = 4.55; P = 0.033), CEA-positive (OR = 5.56, P = 0.018), and ROM-positive (OR = 10.46, P = 0.006) were significant predictive factors for nodal involvement. In multivariate analysis, ROM-positive was an independent predictive factor for nodal involvement (OR = 6.22, P = 0.045).
CONCLUSION: Preoperative serum ROM level was an independent significant predictive factor for nodal involvement in patients with clinical stage I lung adenocarcinoma. Hence, serum ROM level may be a useful biomarker for staging of lung adenocarcinoma.