Predictive Value of Serum Bone Sialoprotein in Patients with Bone Metastasis of Non-Small Cell Lung Cancer

Background: The purpose of this study was to evaluate the diagnostic and prognostic significance of serum bone sialoprotein (BSP) in patients with bone metastasis (BM) from non-small cell lung cancer (NSCLC). Patients and Methods: A total of 146 patients diagnosed with NSCLC and 110 healthy controls were enrolled in this study. The clinical characteristics including clinical stage, pathological type, smoking status, and ECOG performance status were obtained. The mean serum BSP was detected by sandwich ELISA. Results: The mean serum BSP level in individuals with BM was significantly higher than those in non-BM NSCLC and controls (p < 0.001). Receiver operating characteristics (ROC) analysis showed that BSP discriminated patients with BM from non-BM NSCLC patients at the cutoff value of 33.56 ng/ml. Sensitivity and specificity were 77.8 and 81.1%, respectively. Kaplan-Meier analysis showed that subjects with higher BSP levels had a shorter BM-free period than those with lower BSP levels. Cox regression analysis revealed that the BSP level was a predictor for prognosis of BM from NSCLC. Conclusion: Serum BSP is a useful biomarker for the diagnosis of BM from NSCLC, and can be regarded as an independent factor for predicting the prognosis of BM from NSCLC.