Diagnosis value of serum soluble B7-H4 expression in non-small cell lung cancer.

INTRODUCTION: B7-H4, a member of the inhibitory B7 family, can restrain T cell proliferation, activation, cytokine secretion, and may be involved in immune evasion in cancer patients. OBJECTIVES: This aim of the study was to determine the expression level of soluble B7-H4 (sB7-H4) in circulation and to subsequently evaluate the clinical significance of circulating sB7-H4 in patients with non-small cell lung cancer (NSCLC). METHODS: Serum specimens from 128 patients with NSCLC, 100 healthy volunteers (HV), and 80 patients with benign lung diseases (BLD) were collected. The concentrations of sB7-H4 were measured by sandwich enzyme-linked immunosorbent assay. RESULTS: Serum sB7-H4 levels in patients with NSCLC were significantly higher than those in patients with BLD (P < 0.05), or those in HV (P < 0.05). Using a cutoff of 27.8 ng/mL, the sensitivity and specificity of sB7-H4 in differentiating between patients with NSCLC and patients with BLD, and between patients with NSCLC and HV was, 46.9% and 92.5%, and 54.7% and 95.0%, respectively. An area under the curve (AUC) for NSCLC resulting from sB7-H4 (0.863), which was significantly better than any other tumour markers tested including CA125 (0.763), and CEA (0.775). CONCLUSION: In conclusion, assessment of serum sB7-H4 levels could be considered as a diagnostic biomarker for NSCLC.