Upregulation of soluble B7-H3 in NSCLC-derived malignant pleural effusion: A potential diagnostic biomarker correlated with NSCLC staging

Abstract

BackgroundThe B7 family member B7-H3 (CD276) is involved in tumor immunity including Non-small-cell lung cancer (NSCLC). We have previously demonstrated an elevated circulating level of the soluble form of B7-H3 (sB7-H3) in NSCLC patients. However, the expression of sB7-H3 in NSCLC-derived malignant pleural effusions (MPEs) and its clinical significance remain elusive. MethodsWe measured and compared sB7-H3 levels in NSCLC-derived MPEs (n=52) and nonneoplastic pleural effusions (NPEs) (n=47), and then evaluated the diagnostic performance for sB7-H3 in NSCLC-derived MPEs. The correlation between MPE-derived sB7-H3 and clinical characteristics including TNM staging system was also analyzed. ResultsThe median value of sB7-H3 in 52 MPEs and 47 NPEs were 41.60ng/ml (interquartile range: 36.76–51.30ng/ml) and 31.55ng/ml (interquartile range: 26.97–36.63ng/ml) (P<0.0001), respectively. At the proposed cut-off value at 38.41ng/ml, sB7-H3 was capable of discriminating NSCLC-derived MPEs from NPEs with a sensitivity of 67.3% and a specificity of 91.5% respectively. Furthermore, MPEs-derived sB7-H3 was correlated with smoking status (P=0.005), primary tumor size (T factor, P=0.03), regional lymph node dissemination (N factor, P=0.019) and distant metastasis (M factor, P=0.009) of NSCLC patients. ConclusionsUpregulated sB7-H3 expression in MPEs is correlated with TNM stage of NSCLC and may serve as a potential biomarker for NSCLC-derived MPEs.