The prognostic significance of circulating serum amyloid A and CXC chemokine ligand 4 in osteosarcoma

Abstract

BACKGROUND Osteosarcoma is the most common pediatric bone cancer. Despite advances in treatment regimens, the survival rate remains 60–70%. There is an urgent need to identify prognostic biomarkers, so that targeted therapies can be developed to improve the outcome. PROCEDURE Our lab has previously identified that circulating Serum Amyloid A (SAA) and CXC Chemokine Ligand 4 (CXCL4) are upregulated in patients with osteosarcoma. In this study, we tested if they could be used as prognostic biomarkers. We used ELISAs to measure their concentrations in serum samples (n = 233), and immunohistochemistry to examine expressions in primary tumors (n = 37). Prognostic significance of the serum concentrations and tumor expressions of the biomarkers was then evaluated. RESULTS Patients with “High SAA” and “Low CXCL4” circulating levels at diagnosis significantly correlated with a worse outcome (HR = 1.68, p = 0.014), which was independent of the metastatic status. These patients also exhibited a significantly higher rate of poor histological response to chemotherapy. Furthermore, low tumor expression of CXCL4 correlated with poor survival (HR = 3.57, p = 0.005). CONCLUSIONS Our results demonstrate that circulating SAA and CXCL4 may serve as prognostic biomarkers in osteosarcoma. Targeting CXCL4 has been reported, suggesting that it may be exploited as a therapeutic target in osteosarcoma.