Expression of vascular endothelial growth factor in renal cell carcinomas

Vascular endothelial growth factor (VEGF) is an angiogenic factor that may be involved in tumor growth and metastasis. Only a few data concerning the role of VEGF in renal cell carcinomas (RCCs) are available, and no studies have yet evaluated its prognostic value. The aim of the present study was t o assess VEGF expression in a large series of renal tumors with a long foll ow-up, correlated with the usual histoprognostic factors and survival. VEGF immunostaining was performed on formalin-fixed, paraffin-embedded archival tissue from 74 renal carcinomas (62 conventional renal cell and 12 papilla ry carcinomas). Positivity of immunostaining was semi-quantitatively scored by two pathologists. Angiogenesis was evaluated by immunostaining with ant i-CD34 antibodies on serial sections. Cytoplasmic VEGF expression was detec ted in tumor cells in 35% (26/74) of RCCs, including 18 out of the 62 (29%) conventional RCCs and 8 out of the 12 (67%) papillary carcinomas (P=0.02), In the group of conventional RCCs, VEGF expression was positively correlat ed with both nuclear grade (P=0.05) and size of the tumor (P=0.05). Further more, a significant correlation was observed between VEGF expression and mi crovascular count (P=0.05). Finally, cumulative survival rate was significa ntly lower in the group of patients with conventional RCCs expressing VEGF (log rank test, P=0.01). In the Cox model, VEGF expression was a significan t independent predictor of outcome, as well as stage and nuclear grade. Thi s study suggests that VEGF is involved in angiogenesis in conventional RCCs and appears to be a potential prognostic factor in these tumors.