The American Cancer Society predicts that there will be over 56,000 new cases of renal neoplasms in the coming year in the United States and that 13,000 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 (conventional) RCC being the most common histologic subtype (Fig. 32-1). Non–clear cell subtypes include chromophobe, papillary, oncocytoma, collecting duct carcinoma (CDC), and unclassified RCC.
Photomicrographs of clear cell (conventional) 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 type 2 papillary RCC D. showing papillae lined by tall columnar cells, with eosinophilic cytoplasm and high grade nuclear features. (Reprinted with permission from Pheroze Tamboli, MD.)
The incidence of RCC has been increasing over the last several decades. This increase in incidence is partly attributed to the increased use of better-quality abdominal imaging in patients who present with either unrelated or nonspecific complaints. As a consequence, one would predict an increase in the earlier detection of RCC, in earlier stages, and better outcomes associated with definitive therapy. Several reports have examined large epidemiologic databases to determine whether other causative factors may explain the increased incidence of RCC (1,2). Chow and colleagues (2) examined the database of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program looking at patients who were diagnosed with kidney cancer from 1975 through 1995. This database reflects approximately 10% of the US population. They noted an increasing incidence of RCC in men and women regardless of race and also that the increases were greatest for localized tumors, but there was an increased incidence of more advanced and unstaged tumors as well. These data are corroborated in other studies and suggest that there has been an increase in the prevalence of RCC across both gender and racial lines and that, despite the earlier detection, there has not been an improvement in disease-specific mortality rates.
The American Joint Commission on Cancer staging schema for renal cell carcinoma was updated in 2010. Major staging categories are as follows: Stage 1: T1 tumors, which are less than 7 centimeters (cm) in maximum diameter 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, which demonstrate extracapsular invasion, renal or inferior vena caval invasion. Stage 3 also includes tumors with regional node positivity. Stage 4: Extension of the primary tumor ...