RESUMO
OBJECTIVE: To study the immunohistochemical expression of vascular endothelial growth factors in urothelial tumours of bladder and its possible association with tumour characteristics and microvessel density. METHODS: The cross-sectional descriptive study was conducted at the Histopathology Department of the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from July 2011 to December 2012, and comprised cases of non-invasive and invasive urothelial tumours of the bladder. The microvessel density and expression of vascular endothelial growth factors A, C, D were evaluated by immunohistochemistry. Specimens of transurethral bladder biopsies and surgical resection were examined. The cases were classified into non-invasive (stage pTa ) and invasive groups as well as low-grade and high-grade groups. The presence of in-situ component was evaluated in each category. To assess the microvessel density, highly vascularised foci ('hot spots') after immuno-staining with CD34 were quantified for number of vessels per square millimetre and for vascular surface area density. No distinction was made between lymphatic and blood vessels. Vascular endothelial growth factor staining was scored semi-quantitatively. RESULTS: The study examined 100 histopathology specimens, including 90(90%) transurethral bladder biopsies and 10(10%) surgical resection specimens of bladder. There were 45(45%) non-invasive (stage pTa) cases and 55(55%) invasive (stage pT1-4) cases. Besides, there were 43(43%) low-grade (grades 1 and 2) cases, and 57(57%) high-grade (grade 3) cases. Vascular endothelial growth factors A, C and D staining scores showed positive association with stage (p=0.02;p<0.01; p<0.01)and grade (p=0.007;p=0.004; p=0.002) of the tumour. Tumours with in-situ component showed association with number of vessels per square millimetre (p<0.01) and vascular surface area density (p=0.02). CONCLUSIONS: Parameters like vascular endothelial growth factor and microvessel density need to be studied further for selection of cases with potential for targeted therapy.
