Histologic Tumor Necrosis Is an Independent Prognostic Indicator for Clear Cell and Papillary Renal Cell Carcinoma

Histologic tumor necrosis (TN) has been reported to indicate a poor prognosis for different human cancers. In papillary renal cell carcinoma (RCC), data regarding the prognostic impact of TN are conflicting. We retrospectively studied the pathology records of 2,333 consecutive patients who underwent nephrectomy from 1984 to 2006 at a single tertiary academic center. In multivariate analyses regarding clear cell RCC, the presence of histologic TN was an independent negative prognostic factor for metastasis-free (hazard ratio [HR], 2.32; confidence interval [CI], 1.86-2.9; P < .001) and overall (HR, 1.52; CI, 1.31-1.76; P < .001) survival. Regarding papillary RCC, the presence of histologic TN represented an independent predictor of metastasis-free (HR, 5.22; CI, 2.2-12.5; P < .001) and overall (HR, 1.69; CI, 1.11-2.58; P = .015) survival. Our findings suggest that the presence of TN is an independent predictor of clinical outcome in clear cell and papillary RCC. Thus, histologic TN might be a reliable prognostic indicator and should, therefore, routinely be examined during pathologic analysis of RCC specimens. During the last decade, enormous advances in the development of novel anticancer drugs for the treatment of metastatic renal cell carcinoma (RCC) have driven the replacement of nonspecific monotherapy with immunomodulating agents with compounds that selectively target clearly defined molecular pathways, such as vascular endothelial growth factor and mTOR inhibitors. 1 The successful introduction of these clinically efficient targeted drugs in the setting of metastatic disease has prompted the initiation of adjuvant treatment trials with some of these agents for high-risk patients with earlier tumor stages. 2 Considering the high costs and toxic effects of most of these drugs, the accurate identification and validation of prognostic factors that might predict the development of distant metastases might enable a better risk-stratified strategy for patient selection for adjuvant treatment modalities. 3 The diagnosis of RCC comprises different histologic subtypes, including clear cell, papillary, chromophobe, collecting duct, and not otherwise specified cases. 4