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

This study was initiated in order to define the (co-)expression patterns of target receptor tyrosine kinases (RTKs) in human gastric adenocarcinoma and to correlate them with clinicopathological parameters.

The (co-)expression pattern of VEGFR1, VEGFR2, VEGFR3, PDGFRalpha, PDGFRbeta and EGFR1 was analyzed in 56 samples of human gastric adenocarcinoma and correlated with staging and survival.

VEGFR1, VEGFR2, VEGFR3, PDGFRalpha, PDGFRbeta and EGFR1 were expressed at relevant levels in 79%, 50%, 50%, 63%, 55% and 30%, respectively. VEGFR2, VEGFR3, and PDGFRbeta were significantly co-expressed. Thirty-four percent 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. Expression of VEGFR1, VEGFR2, VEGFR3, PDGFRalpha, PDGFRbeta and EGFR1 in gastric adenocarcinoma did not significantly correlate with a higher pT-category, the presence of lymph node metastasis (pN+) or overall survival. However, a trend towards a higher pT-category was seen for expression of VEGFR1 without reaching statistical significance.

The data obtained reveal that specific RTKs are significantly co-expressed. However, co-expression of RTKs did not impact on staging or survival. It has to be further analyzed, if the expression of the respective ligands is of higher relevance than the expression of the receptor itself.