Angiogenesis in poorly differentiated medullary carcinoma of the stomach.

We studied the role of angiogenesis in patients with medullary type poorly differentiated adenocarcinoma (MTPDA) of the stomach. Immunohistochemical analyses were conducted using antibodies against factor VIII (endothelial cells), vascular endothelial growth factor (VEGF) and its receptors (KDR andflt-1), and basic fibroblast growth factor (bFGF) and its receptors (bek andflg). Archival specimens of MTPDA (n=22) and non-MTPDA (n=47) were studied. The expression of VEGF and bFGF, the vessel count, and positivity of KDR on endothelium were all significantly higher in MTPDA than in non-MTPDA. The vessel count correlated with the VEGF expression in MTPDA. The vessel count and VEGF expression increased with the increasing stage of disease in MTPDA but not in non-MTPDA. The expression of bFGF and its receptors did not correlate with the vessel count and stage of disease in either type. These findings thus suggest that the biological behavior of medullary type poorly differentiated adenocarcinoma of the stomach is angiogenesis-dependent. The correlation of the VEGF expression and its endothelial receptors with the vessel count and the stage of disease thus suggests that VEGF is a factor responsible for the induction of angiogenesis in this type.