Considering the recently stated suggestion of neovascularization being implicated in myelodysplastic syndromes (MDS) pathogenesis, we evaluated multiple morphometric microvascular characteristics in MDS, in relation to clinicopathologic factors and prognosis. Trephines from 50 newly diagnosed MDS patients were immunostained for factor VIII and compared to those from 20 controls, 10 chronic myelomonocytic leukemia (CMML) and 12 acute myeloid leukemia (AML) patients. Quantitation of microvessel density (MVD), area, total vascular area (TVA), major and minor axis length, perimeter, compactness, shape factor, Feret diameter, and the number of branching vessels was performed by image analysis. Overall, the MDS group had significantly higher MVD, TVA, minor axis and shape factor values and significantly lower compactness than the control group. AML was characterized by increased vascularity compared to MDS and CMML, as well as by the presence of flattened microvessels (lower values of shape factor). Hypercellular MDS showed higher MVD. RA/RARS displayed larger caliber vessels than RAEB, which explains the favorable prognostic effect of increased size-related parameters on progression and/or survival. Moreover, decreased compactness and MVD were independent predictors of longer progression-free survival. It is concluded that angiogenesis is involved in the conversion of normal marrow to MDS and ultimately to AML and that disease progression within MDS is accompanied by qualitative alterations of the microvascular network. Furthermore, size-related parameters affect survival, while shape-related parameters and MVD are more influential with regard to progression-free survival. Leukemia (2001Leukemia ( ) 15, 1369Leukemia ( -1376

Astrocytic brain tumours, particularly malignant astrocytomas, are recognized to be highly vascular neoplasms with potent angiogenic activity. Recent research has shown that quantification of microvessel density (MVD), as a measure of the degree of angiogenesis, constitutes a strong prognostic indicator in patients with astrocytomas. However, the significance of other morphometric aspects of microvessel network has not been tested so far. In this report, histological sections from 70 astrocytomas (grades II to IV), immunostained for CD34, were evaluated by image analysis for the quantification of MVD, total vascular area (TVA), and microvascular branching, as well as several morphometric parameters related to vessel size or shape. Minor axis length increased with grade (P = 0.045) but MVD and TVA presented a peak in grade III (P = 0.033 and P < 0.001, respectively). Size and shape related parameters affected survival in univariate analysis of grade IV and grades II/III, respectively. In multivariate analysis, only branching counts, along with age and grade, were the independent predictors of survival. Although MVD, TVA and branching counts were adversely related to disease-free survival in grades II and III (univariate analysis), only TVA remained statistically significant in multivariate analysis. It is concluded that TVA and branching counts are prognostically more informative than MVD for patients with diffuse astrocytic tumours.

Hypoxia-inducible factor (HIF)-1alpha is a transcription factor that promotes ischaemia-driven angiogenesis. The aim of this study was to determine the relation of HIF-1alpha to vascular endothelial growth factor (VEGF; an important angiogenic molecule in brain tumours), p53 expression, angiogenesis, proliferative potential and clinical outcome in a large series of diffuse astrocytomas. Expression of HIF-1alpha, VEGF, Ki-67 (a proliferation-associated marker) and p53 was determined immunohistochemically in 83 adult patients with supratentorial diffuse astrocytomas. Microvessels, highlighted by means of anti-CD34 immunohistochemistry, were enumerated with computer-assisted image analysis. Although HIF-1alpha and VEGF were expressed in the majority of cases, their levels increased significantly with increasing grade and proliferative potential. HIF-1alpha positively correlated with microvessel counts and VEGF with total vascular area and the presence of rounder vessel sections. There was a positive correlation of VEGF with p53 expression in astrocytomas and anaplastic astrocytomas. In univariate analysis, both VEGF and HIF-1alpha were associated with shortened survival in the entire cohort, but lost significance when grades II/III and grade IV were analysed separately. Multivariate analysis revealed that the combination of HIF-1alpha with grade was a significant prognostic indicator. HIF-1alpha expression may be used to refine the prognostic information provided by grade in patients with diffuse astrocytomas. Its adverse prognostic effect is most likely mediated by hypoxia, the driving force for HIF-1alpha accumulation.

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Various morphometric characteristics of microvessels, highlighted by means of anti-CD34 immunohistochemical staining, were evaluated in the bone marrow of 52 patients with chronic myeloid leukemia (CML) in chronic phase, in relation to several clinicopathologic parameters. Twenty control bone marrows and 15 cases of CML in blastic phase were also studied. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related parameters were quantitated in the region of most intense vascularization using image analysis. Overall, the group of chronic phase CML had higher MVD and size-related parameters and more branching microvessels than controls. Blastic phase was characterized by increased numbers of microvessels with a rounder shape and smaller caliber than chronic phase. A positive correlation emerged between marrow fibrosis and MVD as well as between white blood cell counts and rounder vessel sections. No relationship existed between microvascular parameters and Hasford or Sokal prognostic scores. In univariate analysis, overall and progression-free survival were adversely affected by MVD, size-related parameters, increased platelet count, age and spleen size. Multivariate analysis indicated that microvessel area was related to progression-free survival, whereas both MVD and area were significant prognosticators of overall survival, even when Hasford or Sokal scores are introduced into the model. Our data suggest that changes in angiogenic parameters may participate in the conversion of normal marrow to CML and ultimately to blastic transformation. More importantly, MVD and microvessel caliber are significant predictors of patient survival and progression.