Prognostic Role of Tumor Necrosis, Microvessel Density, Vascular Endothelial Growth Factor and Hypoxia Inducible Factor-1α in Patients with Clear Cell Renal Carcinoma after Radical Nephrectomy in a Long Term Follow-up

Abstract

Angiogenesis is a critical step in the growth, invasive progression and metastatic spread of solid tumors. We investigated the importance of tumor necrosis, and microvessel density (MVD), vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1α (HIF-1α) immunohistochemical expression in a large series of clear cell renal carcinomas treated with radical nephrectomy and assessed the prognostic value of their expression in terms of patient survival at long-term follow up. Fifty patients with clear cell RCC were examined. The features considered when evaluating the patients were age, tumor size and grade, intratumoral vascular and renal capsula invasion, histological necrosis, and MVD, vascular and tumoral cell VEGF, and vascular, tumoral cytoplasmic and nuclear HIF-1α expression on the histologic specimens. All considered parameters were correlated with patient specific survival. Mean age was 62.06 ± 6.8 years. Median follow-up was 191.66 months; median survival was 120.86 months. Twenty-one patients developed metastases in the follow-up. Tumor necrosis, microvascular invasion and renal capsula infiltration are more likely to occur in high stage and grade RCC; cytoplasmic HIF-1α is highly expressed in high grade RCC. Survival is dependent upon tumor stage and grade, the presence of intratumoral vascular invasion and capsular infiltration, and tumor necrosis; MVD also resulted as being an important prognostic factor. VEGF and HIF-1α correlate with prognosis in high stage tumors where VEGF is the most important independent prognostic factor for cancer specific death. The histological and immunohistochemical parameters considered in our study can influence disease recurrence and survival in RCC.