A comparison of the vascular density of VEGF expression with microvascular density determined with CD34 and CD31 staining and conventional prognostic markers in renal cell carcinoma.

AIM: The aim of this study was to compare the vascular density of Vascular endothelial growth factor (VEGF) expression with microvascular density determined by CD34 and CD31 with conventional prognostic parameters.

METHODS: The study involved 50 renal cell carcinoma (RCC) cases. VEGF, CD34, and CD31 were stained by immunohistochemistry, and then preparations were evaluated by two pathologists under light microscopy. The whole tumor area was scrutinized in all the sections. In the evaluation of VEGF, due to the lack of homogenous staining within the tumor, two parameters, distribution and intensity of expression, were evaluated semiquantitively. In the evaluation of microvascular density with CD34 and CD31 staining, three hot areas with the highest density were determined. In x200 magnification of these areas, on a single plane, the quantity of vascular structures with lumens was determined.

RESULTS: Intensity of VEGF Expression was higher in papillary type carcinoma of kidney parenchyma (P = 0.014) and it was significantly correlated with tumor stage (P = 0.013), survival time (P = 0.01), and tumor size (P = 0.035). Distribution of VEGF expression was also higher in papillary RCC (P = 0.055) and it was significantly correlated with tumor stage (P = 0.043) and tumor size (P = 0.039). Vascular density determined with CD34 staining was higher in conventional RCC (P < 0.05); in addition, it was significantly correlated with distribution and intensity of VEGF expression (P < 0.05) and tumor stage (P < 0.05). Vascular density determined with CD31 staining was not significantly correlated with tumor type, tumor stage, nuclear grade, and survival time.

CONCLUSIONS: Intensity and distribution of VEGF were higher in papillary RCC. Both parameters were significantly correlated with tumor size, stage, and vascular density determined with CD34 staining. Intensity of VEGF was also significantly correlated with capsule invasion. Vascular density determined with CD34 staining, however, was higher in conventional RCC, and it was correlated with tumor size and stage.