Does expression of receptor tyrosine kinases in gastric adenocarcinoma correlate with clinicopathological parameters?

Introduction: The prognosis for patients with gastric cancer depends on the stage of the disease. Radical surgery and lymph node dissection represent the only curative intent and are the standard therapeutic option for patients with limited disease. As new multi-targeted receptor tyrosine kinase inhibitors (RTK) are ermerging in the therapy of diverse malignomas, our aim was to analyze the relevance of the targeted receptor tyrosine kinases on local growth, lymphatic dissemination and overall survival in gastric adenocarcinoma. Methods: The (co-)expression pattern of VEGFR1, VEGFR2, VEGFR3, PDGFRα, PDGFRβ and EGFR1 was analyzed by RT-PCR in 56 consecutive samples of human gastric adenocarcinomas and correlated with tumor stage and survival. Results: 34% of gastric adenocarcinoma samples revealed a co-expression of 6 receptors, 27% expressed 5 receptors and only 23% showed expression of 3 receptors or less. Co-expression of VEGFR1-3 was found in 61% of all gastric adenocarcinoma samples. Most interestingly, expression of VEGFR1, VEGFR2, VEGFR3, PDGFRα, PDGFRβ and EGFR1 in gastric adenocarcinoma did not significantly correlate with the presence of lymph node metastasis, higher pT-category or overall survival. However, a trend towards a higher pT-category was seen for expression of VEGFR1 and 2 without reaching statistically significance. Conclusion: Our data implicate that VEGFR1-3, PDGFRα/β and EGFR1 expression profiles do not exert an impact on tumor progression or survival in gastric adenocarcinoma. Therefore, results of currently running phase II studies with multi-target RTK-inhibitors such as Sunitib or Sorafinib have to be analyzed and correlated.