Heterogeneity in microvascular density in lung tumours: comparison with normal bronchus

Abstract

Summary The aim of this study was to test the hypotheses that (a) microvascular density (MVD) measured in histological sections of resected non-small cell lung carcinomas is an index of angiogenesis and (b) the measurement of MVD in a single block is representative of the overall MVD of the tumour. MVD was quantitated in one block per specimen of 60 lung tumours and nine normal lung tissues, and in 47 blocks taken from different regions of four tumours. Blood vessels were stained with antibody to von Willebrand Factor and MVD was quantitated using two methods: average density throughout the section (a-MVD) and density in the most vascularized area or 'hot spot' (h-MVD). Similar h-MVD values were found in tumours and in normal bronchus, whereas a-MVD was greater in the latter (P < 0.01). When 47 blocks from four tumours were analysed, inter-tumour variation was significant (P < 0.001) in spite of significant intra-tumour variation. The highest MVD value was not necessarily found in the periphery of the tumour. The four tumours were ranked into either two or four tiers according to their overall MVD. In 50 random selections of one block per tumour, the correct ranking was achieved in 68-74% of cases with the two-tier ranking and in 6-16% of cases with the four-tier ranking (h-MVD and a-MVD values respectively). These results suggest that elevated MVD values do not necessarily represent angiogenesis in non-small cell lung carcinomas. When only one block per tumour is examined, the chance of obtaining an accurate estimate of the vascularity of that tumour may be lower than 68%.

Microvessel Density Is Associated with VEGF and α-SMA Expression in Different Regions of Human Gastrointestinal Carcinomas

“…We used the polyclonal anti-FVIII antibody for the MVD assessment, whose reproducibility of blood vessels immunostaining in different regions from GITC was higher compared to the anti-CD31/PECAM antibody immunostaining (data not shown). These results were in concordance with other comparative studies of MVD that used these antibodies in breast, prostate, gastric, esophageal and lung cancer [3,12,13]. The FVIII expression observed in endothelial cells cytoplasm corresponding to sprouts in the CT and P regions from GITC could indicate the occurrence of early angiogenesis events in these tumors.…”

A review of the development of tumor vasculature and its effects on the tumor microenvironment

“…Although the data are limited, it seems that tumors are also more vascularized overall. This is not trivial – the opposite has been reported for esophageal SCC57 and lung cancer 58. However, tumor vascularity is highly heterogeneous, and there can still be regions of head and neck cancers, in which the vascularity is comparable to or even less than that in normal tissue.…”

EGFR and microvessel density in canine malignant mammary tumours

“…Subsequently, under a 200Â magnification the stained microvessels were counted. Three different fields were counted in each of these areas (Schor et al, 1998). The somatory of the number of microvessels (MVD) was subsequently calculated from the two vascular hot spots.…”