Background: Erythropoietin-producing hepatocellular (Eph) receptors are the largest subfamily of receptor tyrosine kinases that have been investigated as a possible target for molecular targeted therapy of various cancers.
Methods: Patients (n = 222) who underwent gastrectomy for primary gastric cancer were enrolled in this study. Tumor protein expression of EphA1 and EphB6 in surgically resected specimen was investigated using immunohistochemistry. The associations between expression of EphA1 and EphB6 and clinicopathological factors and prognosis were analyzed.
Results: High expression of EphA1 was associated with undifferentiated histology (P = 0.002), depth of tumor (P < 0.001), lymph node metastasis (P = 0.001), venous invasion (P = 0.015), stage (P = 0.001), and remote metastasis or recurrence (P < 0.001). In univariate analysis, patients with high expression of EphA1 had significantly poorer overall survival and relapse-free survival compared with patients with low EphA1 expression. The expression level of EphB6 was not associated with any clinicopathological factors and patient survival. Multivariate analysis indicated that depth of tumor [hazard ratio (HR) 9.26, 95 % confidence interval (CI) 0.03-0.46, P = 0.003], lymph node metastasis (HR 9.26, 95 % CI 0.07-0.39, P < 0.001), and high expression of EphA1 (HR 1.86, 95 % CI 0.29-0.99, P = 0.048) are independent prognostic factors for relapse-free survival.
Conclusions: EphA1 is a possible target of molecular targeted therapy of gastric cancer.