Serum osteopontin as a prognostic marker in patients with lung cancer

Abstract

Introduction: Osteopontin (OPN) is a multifunctional cytokine that has been involved in cancer development, angiogenesis and metastasis. OPN is overexpressed in lung cancer and it has been evaluated as a biomarker of its progression. Increased OPN sputum levels have been detected in patients with COPD. Lung cancer (LC) and COPD are both smoking-related diseases and may share common pathogenetic mechanisms.

Objective: We measured serum levels of OPN in patients with LC with and without coexistent COPD in order to evaluate its prognostic performance on 1-year mortality.

Methods: We recruited 167 patients with LC, mean age 66±10 years, 119 current smokers, 85 with concomitant COPD, whereas 20 patients with COPD served as a control group. All subjects underwent lung function tests and serum collection for OPN measurement. All patients were optimally treated for LC and COPD according to their attending physicians and were followed for one year or until death.

Results: Patients with LC (with or without concomitant COPD) presented higher serum OPN levels compared to those with COPD alone [median IQR 36 (23-54) vs 45 (24-69) vs 27(15-34) ng/ml respectively, p=0.006]. No significant difference was observed in serum OPN between the LC groups (with and without COPD, p=0.171). In multivariate Cox regression analysis, serum OPN > 50ng/ml was an independent predictor of 1-year mortality (HR 3.014 95% CI 1.821-5.130). SCLC was another significant predictor of 1-year mortality compared to NSCLC. (HR 1.19 95% CI 0.86-1.3).

Conclusion: Serum OPN with a cut-off value of 50ng/ml could predict 1-year mortality in patients with lung cancer. The co-existence of COPD did not seem to affect its prognostic value.