ERG and nestin: useful markers of immature vessels and novel prognostic markers in renal cell carcinoma.

objectivesRenal cell carcinoma (RCC) accounts for approximately 90% of all renal malignancy. Because a rich vasculature is an outstanding feature of RCC, information on the blood vessels of RCC might explain its tumor characteristics. Several researchers have noted the effects of tumor vessels on the clinicopathologic characteristics and prognosis of tumors; however, a clear association has not been established. We hypothesized that the immaturity of the neovasculature may be an important clinicopathologic characteristic forprognosis of RCC patients. ERG and nestin are new vascular markers that regulate vascular homeostasis and angiogenesis. Therefore, in the present study, we investigated how ERG and nestin were expressed with respect to tumor characteristics. MATERIALS AND

methodsIHC staining for ERG, nestin, CD31, and CD34 was performed for 217 renal tumors, including clear-cell RCC (ccRCC; n = 184), papillary RCC (pRCC; n = 14), chromophobe RCC (chRCC; n = 14), and oncocytoma (n = 5).

resultsVascular endothelial cells from normal kidney consistently showed strong nuclear expression of ERG and nestin. Conversely, a loss of ERG and nestin expression was observed in endothelial cells of some tumor blood vessels, which was associated with tumor progression. In particular, the loss of ERG expression was significantly associated with progression-free survival and overall survival (univariate analyses:

conclusionA loss of ERG and nestin expression is associated with tumor progression, and loss of ERG is a powerful prognostic marker for ccRCC.