Microvascular density and endothelial area correlate with Ki-67 proliferative rate in the canine non-Hodgkin's lymphoma spontaneous model.

Experimental and clinical data indicate that tumor progression and malignancy are associated with increased angiogenesis and higher Ki-67 proliferation rate. Furthermore, increased angiogenesis and higher Ki-67 proliferation rate are associated with a poor prognosis, in both solid and hematological malignancies. However, no data have been published concerning the relationship between angiogenesis and Ki-67 proliferation rate in canine non-Hodgkin's lymphoma (NHL), a neoplasm that shares several biological and clinical characteristics with human NHL. This study has evaluated the relationship between angiogenesis and Ki-67 proliferation rate in a series of 58 canine NHL. Results showed that microvascular density (MVD), endothelial area (EA) and Ki-67 (MIB-1) are significantly correlated and that all the above indexes paralleled with the malignancy degree of NHL. These data suggest a biological link between angiogenesis and Ki-67 proliferation rate in canine NHL, which represents an interesting model to study the role of angiogenesis and proliferative activity as inter-species pathways of tumoral malignancy and biological aggressiveness.

Vascular endothelial growth factor concentrations in the plasma-activated platelets rich (P-APR) of healthy controls and colorectal cancer patients.

Vascular endothelial growth factor (VEGF) is known to play a key role in tumour angiogenesis. Our preliminary published data suggest that plasma-activated platelets rich (P-APR) rather than other plasma compartments (i.e. plasma, plasma-platelets poor) or serum is the more suitable blood fraction for measuring VEGF in a miscellaneous series of gastrointestinal cancer patients. The aim of this confirmatory study was to assess VEGF in P-APR blood compartments of 30 healthy control subjects (HCS) and a homogeneous series of 62 colorectal cancer patients (CRCP), prospectively collected, to evaluate its possible clinical-biological significance. Samples of plasma (P) in both sodium citrate (SC) and sodium citrate-theophylline-adenosine-dipyridamole (CTAD) were collected from venous blood. After the centrifugation and separation methods VEGF levels were detected by ELISA in P-APR. The best differentiation between HCS and CRCP in VEGF level was seen for P-APRCTAD (median value: 255 pg/ml versus 142 pg/ml; p=0.000 by Mann-Whitney U test). No significant correlation among the P-APR VEGF concentrations and the main clinical pathological features was found. We suggest that P-APRCTAD fraction, obtained according to well standardised conditions, could represent the suitable blood compartment for the assessment of VEGF as marker of malignant intestinal transformation.