Introduction and epidemiology
Kidney cancer is a relatively common urological cancer, accounting for approximately 2% of all adult cancers. In the UK during 2003, 6683 new kidney cancer cases were registered. Of these 4059 cases were male and 2624 cases were female making it approximately two times more common in males. In the USA, the American Cancer Society predicts that there will be approximately 51,200 new cases of kidney cancer (31,590 in men and 19,600 in women) in 2007 and some 12,890 people will die from this disease.
The incidence appears to be rising not only in Western societies owing to a variety of reasons, including the increased use of cross-sectional imaging, but also throughout the world. Risk factors for kidney cancer include obesity, smoking, and hypertension. Other implicated factors are environmental exposure to asbestos, end-stage renal disease, and hemodialysis. Long-term dialysis may result in acquired renal cystic disease, predisposing to the development of multifocal and bilateral renal cancers.
The histological subtypes of kidney cancers are listed in Table 1.1 and discussed in more detail in Chapter 2. This chapter, and indeed most of this book, will concentrate on adult renal cell carcinoma (RCC). Traditionally RCCs were often detected late as they can grow to a relatively large size because of their retroperitoneal location.