Epidemiology of renal cell carcinoma

The incidence of kidney cancer has been increasing for the past several decades. It ranks the second most common neoplasm found in the urinary system. The majority of kidney cancers are renal cell carcinomas (RCC, < 85 %), and of these, clear cell tumors are the most common histologic type. Higher incidence is observed in industrialized western countries compared to less well-developed nations. Gender and ethnic disparity are observed for RCC. Current consensus is that cigarette smoking, hypertension, and obesity are three established risk factors for RCC. However, the exact biological mechanisms that underlie for these risk factors are still not fully elucidated. Energy balance that incorporates effects of energy intake and expenditure has attracted much attention in recent years. Diet/intake of nutrients, energy consumed, level of physical activity, and weight change could jointly affect RCC risk. Other risk factors that have been implicated include type II diabetes and other chronic medical conditions, occupational/environmental exposures, parity, and number of offspring. Recent genome-wide association studies (GWAS) have identified multiple chromosome regions harboring RCC susceptibility loci. A number of intermediate phenotypic markers, such as suboptimal DNA repair capacity, short telomere length, and low mitochondrial DNA copy number, have been shown to be associated with risk of RCC. The discovery of additional genetic susceptibility loci through next-generation sequencing (NGS) and intermediate biomarkers using various "omics" approaches, as well as the identification of gene-environment and gene-gene interactions, will all be important next steps to improve our understanding of RCC etiology.