Clinical significance of serum osteopontin levels in lung cancer

Background: Osteopontin (OPN) is a multifunctional glycoprotein associated with lung cancer (LC) via several pathways including tumour angiogenesis. Aims and objectives: The aim of our study was to investigate possible associations between serum levels of OPN in patients with LC and clinicopathological variables, VEGF and MMP-9 levels and overall survival. Methods: We enrolled 51 patients (mean age 66±8.8 years) with primary LC and 30 healthy control subjects. 43 patients were ever smokers and 8 non-smokers, 12 patients had SCLC and 39 NSCLC (18 squamous, 16 adenocarcinoma and 5 NSCLC-NOS) with stage I-II/4, III/18, IV/29. Serum levels of OPN, VEGF and MMP-9 were measured by ELISA. Results: Patients with LC had statistically significantly higher serum OPN levels than controls (45.9[10.5-266.8] vs 16[6.8-29.8] ng/ml, p 23.8 ng/ml, sensitivity for detection of LC was 80.4% and specificity was 86.7%. OPN levels were also found higher in smokers (p=0.019) and in older patients (p=0.026). Moreover, patients with squamous LC had statistically significantly higher OPN levels compared to patients with adenocarcinoma. Additionally, patients with serum OPN levels lower than median value ( Conclusions: OPN levels were increased in patients with LC, and higher levels were correlated with worse survival, therefore suggesting a possible diagnostic and prognostic value of OPN in patients with LC.