High neural precursor cell-expressed developmentally down-regulated 9 expression is a poor prognostic indicator for osteosarcoma

BACKGROUND: This study detected neural precursor cell-expressed developmentally down-regulated 9 (NEDD9) expression in osteosarcoma tissue samples. It also examined the association between NEDD9 expression and clinicopathological features of osteosarcoma. METHODS: The prognostic value of NEDD9 has been verified in multiple solid cancers, but not osteosarcoma. In this study, 45 osteosarcoma paraffin-embedded specimens were accumulated and applied based on immunohistochemistry to identify NEDD9 expression. A correlation linking NEDD9 expression, clinicopathological qualities, and its prognostic significance was assessed to verify whether NEDD9 could be a poor prognosis biomarker. RESULTS: High NEDD9 expression compared to its low expression in osteosarcoma tissue was shown in the immunohistochemical assay. The percentage of high and low NEDD9 expression was 62.2% and 37.8% respectively. NEDD9 expression level was significantly associated with metastasis and Enneking stage (P<0.05), while gender, age, tumor size, sites, and histopathological types were not. Univariate analysis showed that metastasis with a hazard ratio (HR) of 2.63 (P=0.003), Enneking stage III (HR =5.44, P=0.009), chondroblastic osteosarcoma (HR =2.59, P=0.014), and high NEDD9 expression (HR =2.79, P=0.002) were prognostic factors contributing to poor overall survival (OS). Moreover, multivariate analysis revealed that nonconventional pathological osteosarcoma (HR =0.17, P=0.010) and NEDD9 expression (HR =6.03, P<0.001) were independent prognostic factors. CONCLUSIONS: High NEDD9 expression in osteosarcoma independently indicated poor clinical prognosis, indicating the possibility that NEDD9 could be a therapeutic target for osteosarcoma.