Tumor angiogenesis is known to be regulated by
growth factors secreted by host and
tumor cells. Despite the importance of
tumor vasculature and angiogenic heterogeneity in solid
tumors, few studies have compared the vasculature in different regions of human
cancer. Blood vessels from different regions of
carcinomas might have morphofunctional implications in
tumor angiogenesis. In the present study, therefore, we have examined the relationship between microvascular density (MVD) and
vascular endothelial growth factor (
VEGF) expression and alpha smooth muscle actin (α-SMA) expression in the center of the
tumor (CT), periphery (P) and
metastasis (M) regions from gastrointestinal
carcinomas (
GITC), as well as the association of MVD with clinicopathological factors. Surgically resected specimens corresponding to the CT, P and M from 27 patients were examined for FVIII,
VEGF and α-SMA by immunohistochemistry. The MVD was not significantly different in the CT, P and M regions from
GITC. The MVD in the
VEGF positive group was significantly higher than in the
VEGF negative group (CT, p = 0.034; P, p = 0.030; M, p = 0.032). The MVD as a function of α-SMA expression was also significantly higher in the CT and P region compared to the M region (p = 0.0008). In conclusion, the MVD association with
VEGF and α-SMA expression, might indicate an increase of the number of neoformed and preexisting blood vessels uniformly or partially covered by pericytes in different regions of
GITC, suggesting that not only MVD and
VEGF are important parameters to the
tumor vasculature, but also blood vessels maturation is a crucial factor for gastrointestinal
tumor angiogenesis regulation and possible target of vascular
therapy.