Abstract 459: The use of circulating SAA and CXCL4 to predict outcome of osteosarcoma at diagnosis

Abstract

Abstract Background: Osteosarcoma is the most common malignant bone tumor in children. The survival rate of osteosarcoma is 60-70%, which has remained stagnant for the past four decades. Identifying biomarkers that can better prognosticate osteosarcoma patients and guide therapies would improve survival of this disease. Material and Methods: In this study, we used ELISA to evaluate the expression of two previously identified circulating biomarkers, namely Serum Amyloid A (SAA) and CXC Chemokine Ligand 4 (CXCL4), in a large cohort of serum samples (n = 233) obtained at from the Children's Oncology Group at initial diagnosis. The biomarkers’ expression was correlated with survival and evaluated for prognostic significance in the OS patients. Results: Analysis showed that patients with high SAA and low CXCL4 levels had significantly poorer outcome (p = 0.014, HR = 1.68), which was independent of initial metastasis status. The 5-year overall survival rates for the “high-risk” and “low-risk” groups were 47% (95% CI; 36% - 62%) and 64% (95% CI; 57% - 72%), respectively. In addition, low tumor expression of CXCL4 correlated with poor survival (p = 0.017) in an osteosarcoma tissue microarray. In conclusion, this study reports a novel prognostic model consisting of high SAA and low CXCL4 levels in sera that prognosticates osteosarcoma patients at initial diagnosis. This model could serve as the basis for future biomarker-guided clinical trials by incorporating targeted therapy for the poor prognostic population. Citation Format: Ricardo J. Flores. The use of circulating SAA and CXCL4 to predict outcome of osteosarcoma at diagnosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 459.