Prognostic implications of microvessel morphometry in diffuse astrocytic neoplasms

Abstract

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.

Correlations between Perfusion MR Imaging Cerebral Blood Volume, Microvessel Quantification, and Clinical Outcome Using Stereotactic Analysis in Recurrent High-Grade Glioma

“…[1][2][3][4][5][6][7][8][9][10] Most glioma studies have measured angiogenesis by using vessel number counts or MVD. [11][12][13][14] Both precedent and the relative ease of MVD calculation have made this technique a logical first choice to study outcome; however, while MVD shows good predictive power for non-central nervous system tumors, the correlation with glioma survival has been marginal at best.…”

“…[11][12][13][14] Both precedent and the relative ease of MVD calculation have made this technique a logical first choice to study outcome; however, while MVD shows good predictive power for non-central nervous system tumors, the correlation with glioma survival has been marginal at best. [1][2][3][4][5][6] Specific characteristics of glioma angiogenesis are likely to account for the poor correlations with survival. HGGs are often characterized as having large-lumen microvessels that are few in number, large in area, and linked with aggressive behavior and poor prognosis.…”

“…HGGs are often characterized as having large-lumen microvessels that are few in number, large in area, and linked with aggressive behavior and poor prognosis. 4,[6][7][8] These large-lumen microvessels can be composed of either a single lumen or multiple lumina, the latter having a "glomeruloid" appearance that is a histologic hallmark of grade IV tumors. MVD poorly characterizes the morphometric complexity of these large-lumen microvessels, because area and number are often inversely related.…”

“…MVD poorly characterizes the morphometric complexity of these large-lumen microvessels, because area and number are often inversely related. 1,4,[6][7][8]14,15 In contrast, the MVA of the tumor vessels may provide a more salient clinical biomarker of glioma outcome. This assertion is supported by studies showing that MVA correlates more strongly with survival compared with MVD, even in tumors with similar histologic grades.…”

“…This assertion is supported by studies showing that MVA correlates more strongly with survival compared with MVD, even in tumors with similar histologic grades. 1,4,[8][9][10] Despite this evidence, histologically quantifying MVA remains a research tool because the technique is time-consuming, labor-intensive, and thus impractical for routine clinical use. 6,7 For Ͼ2 decades, DSC-MR imaging has been used to study glioma angiogenesis.…”