The aim of the current study was to evaluate the expression of
vascular endothelial growth factor (
VEGF) and the microvascular density in canine
soft-tissue sarcomas. Immunohistochemistry for
VEGF expression was performed on 20 canine
neoplasms by the
streptavidin-
biotin-
peroxidase method using an anti-
VEGF mouse
monoclonal antibody (ab-119). The volume fraction of microvessels in the
sarcomas was quantified in
hematoxylin and
eosin-stained tissue sections. At least 10 fields of view (40x magnification) per
neoplasm were analyzed by positioning a grid with 100 points and counting the microvessels that fell into the intersection points. This percentage was considered the volume fraction of these microvessels in the
tumor section.
VEGF expression was detected in 65% of the
neoplasms. In 92.3% of the
neoplasms, the expression occurred in the peritumor region; in 46.15%, in the intratumor region; and in 38.46%, the expression was present in both regions. The cells responsible for
VEGF expression were fibroblasts and macrophages in the peritumor region or in the pseudocapsule and neoplastic cells in the intratumor region. Greater intratumoral
VEGF was expressed in
hemangiopericytomas (P = 0.04). No difference was present in the volume fraction of
tumor microvessels between
VEGF-positive and
VEGF-negative
neoplasms (P = 0.3416) or for the different types of
neoplasms (P = 0.5). The results of this study suggest that
VEGF participates in the angiogenesis of
soft-tissue sarcoma in dogs. Additional research will be necessary to elucidate the contribution of
VEGF to the progression of
malignancy.