Clinical significance of long non-coding RNA EWSAT1 as a novel prognostic biomarker in osteosarcoma.

OBJECTIVE: Long non-coding RNA EWSAT1 (EWSAT1) has been identified as a tumor promoter in several tumors, but its prognostic values in osteosarcoma have not been reported. The purpose of this study was to explore the association between EWSAT1 expression and prognosis of osteosarcoma patients. PATIENTS AND METHODS: EWSAT1 levels were examined in 176 osteosarcoma tissues and matched normal bone tissues by qRT-PCR analysis. The associations of EWSAT1 expression with clinicopathologic variables were analyzed. The survival curves were calculated by the Kaplan-Meier method. The Cox proportional hazards regression model was used to identify independent prognostic factors with independent prognostic for overall survival (OS) and disease-free survival (DFS). RESULTS: We found that EWSAT1 levels were significantly higher in osteosarcoma tissues compared with matched non-cancerous tissues (p<0.01). The level of EWSAT1 expression was significantly associated with clinical stage (p=0.001) and distant metastasis (p=0.011). Then, Kaplan-Meier analysis showed that high EWSAT1 expression level was associated with poorer OS (p=0.0007) and DFS (p=0.0010). Furthermore, Cox multivariate analyses demonstrated that EWSAT1 expression was an independent prognostic factor for both OS (p<0.001) and DFS (p=0.001) in osteosarcoma patients CONCLUSIONS: Increased EWSAT1 expression was associated with poor outcomes in osteosarcoma patients, and EWSAT1 could serve as a potential unfavorable prognostic biomarker.