Effect of mast cells on tumor angiogenesis in lung cancer

Background. We conducted a retrospective study to clarify the effect of mas t cells on tumor angiogenesis in lung cancer patients. Methods. Formalin-fixed and paraffin-embedded tumor sections were used in t his study. Parenchymal mast cells were stained with Alcian blue and safrani n O. The number of mast cells per ten fields at a magnification of 200 x wa s counted under light microscopy, and the average count was determined. To highlight the microvessels, endothelial cells were stained with anti-human factor VIII antibody. After the microvessel count was determined, the micro vessels were further stained with Alcian blue and safranin O to show areas of mast cell infiltration. Expression of vascular endothelial growth factor was assessed using a polyclonal antibody. Results. We found a significant correlation between mast cell count and mic rovessel density. This correlation was also observed in patients with adeno carcinoma (p < 0.001) as well as in patients with squamous cell carcinoma ( p < 0.01). Double staining of the microvessels showed highly angiogenic are as densely populated with mast cells. Although we detected a slight trend t oward a correlation between vascular endothelial growth factor expression a nd microvessel density, it was not statistically significant. We found no a ssociation between vascular endothelial growth factor expression and mast c ell count. Conclusions. There appears to be a direct correlation between the number of mast cells and tumor angiogenesis in patients with lung cancer, and this r elationship appears to be independent of vascular endothelial growth factor expression. (C) 2000 by The Society of Thoracic Surgeons.