Combined high NEDD9 expression and E-cadherin loss correlate with poor clinical outcome in gastric cancer

Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a member of the Cas family. Previous studies have revealed that NEDD9 coordinates the focal adhesion kinase and Src signaling cascades that are involved in integrin-dependent adhesion and migration, invasion, cell apoptosis and life cycle, and survival, which may play a role in epithelial-mesenchymal transformation. The aim of this study was to analyze the expression of NEDD9 and E-cadherin in gastric cancer (GC) and evaluate their clinical significance.

NEDD9 and E-cadherin expression was analyzed with immunohistochemistry using tissue microarray technique in 435 GC patients who underwent gastrectomy. The NEDD9 expression level was defined by the combination score, which was determined by multiplying the staining intensity score and the proportion score (≥5; NEDD9-high, <5; NEDD9-low). E-cadherin loss was defined as a total loss of staining. The clinicopathologic parameters, overall survival, and disease-free survival rates were analyzed according to the NEDD9 and E-cadherin expression status.

The combined NEDD9 and E-cadherin expression status correlated with lymphatic invasion (P = 0.001), vascular invasion (P = 0.020), and T stage (P = 0.001). Combined high NEDD9 expression and loss of E-cadherin expression status had a worse overall survival rate (P < 0.001) and served as a poor prognostic factor (Hazard ratio 2.49, 95% CI 1.25-5, P = 0.01).

Immunohistochemical staining for NEDD9 and E-cadherin may function as a candidate prognostic marker for gastric cancer in everyday practice, especially when applied in combination.