The American Cancer Society predicts that in 2015 there will be over 64,000 new cases of renal neoplasms in the United States and that 14,000 patients will die as a consequence of disease progression (1). Renal cell carcinoma (RCC) is the most common histology found in kidney tumors, with clear cell RCC (ccRCC) being the most common histologic subtype (Fig. 35-1). Non–clear cell RCC (nccRCC) subtypes include chromophobe, papillary, oncocytoma, collecting duct carcinoma (CDC), renal medullary, translocation, and unclassified RCC.
Photomicrographs of clear cell (conventional) renal cell carcinoma (RCC) with low-grade (A) and high-grade (B) nuclear features. Photomicrographs of a type 1 papillary RCC (C) showing papillae lined by short cuboidal cells and a type 2 papillary RCC (D) showing papillae lined by tall columnar cells, with eosinophilic cytoplasm and high-grade nuclear features. (Used with permission from Pheroze Tamboli, MD.)
Work by Chow et al (1) found the worldwide incidence of RCC appearing to plateau after a steady increase over several decades. To examine the incidence in the United States, the group used the database of the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program to track patients with a diagnosis of kidney cancer from 1977 to 2006. The rate of localized cancer detection has continued to increase, whereas the rates of regional, metastatic, and unstaged RCC have declined. In this work, the mortality rate associated with RCC appears to begin declining in the early 2000s across both gender and racial lines. Although the direct causal relationship for the decline in RCC mortality in this study is unclear, early detection in the era of computed tomography (CT) imaging may be contributing to this finding.
STAGING, EPIDEMIOLOGY, AND RISK FACTORS
The American Joint Commission on Cancer staging schema for RCC was updated in 2010. Major staging categories are as follows: stage 1: T1 tumors that are 7 cm in maximum diameter or less and are confined to the kidney; stage 2: T2 tumors that exceed 7 cm in diameter but are confined to the kidney; stage 3: T3 tumors that demonstrate extracapsular invasion into the perinephric adipose tissue or renal sinus or extend into the renal vein or inferior vena cava (stage 3 also includes tumors with regional lymph node metastasis); and stage 4: extension of the primary tumor into the ipsilateral adrenal gland or beyond Gerota’s fascia or distant metastases (2).
The link between germline genetic mutations and the development of RCC is well established and applies to a small but ...