Cancer of the kidney represents 4% of adult malignancies. Men are more frequently affected than women, and it commonly occurs between the ages of 50 and 70 years. More than 30% of patients present with metastatic disease. The majority of malignant tumours are adenocarcinomas, arising from the proximal renal tubular epithelium. These tumours were previously called hypernephroma because it was believed that they originated from adrenal rests, but they are correctly termed renal cell carcinoma (RCC). The main focus of this chapter is the management of RCC. Transitional cell carcinoma of the renal pelvis accounts for 5% of all renal malignancies, and is covered separately at the end of the chapter.
Types of kidney tumour
Kidney tumours can be benign, malignant primary or metastatic. Benign tumours include cysts (simple, complex, multiple), inflammatory (infection, infarction), adenoma and oncocytoma. Malignant primary tumours include RCC, lymphoma, sarcoma and renal pelvis tumours (5% of malignant renal cancers arise from the renal pelvis, and more than 90% of these are transitional cell carcinoma).
The kidneys are retroperitoneal structures that lie between the eleventh rib and the transverse process of the third lumbar vertebral body, each approximately 11 cm in length, the right lying slightly lower than the left. Each kidney is surrounded by perinephric fat which in turn is covered by Gerota's fascia. The right kidney abuts the liver and stomach and the left, the spleen, stomach and pancreas. The lymphatics drain along the renal vessels, on the right draining to paracaval and aortocaval nodes, and on the left to the para-aortic region.
Incidence and epidemiology
Over 10,000 new cases of kidney cancer were diagnosed in the UK in 2011 resulting in approximately 4200 deaths (Cancer Research UK website accessed July 2014). In the last 10 years kidney cancer incidence rates in the UK have increased by almost a third, and unlike in some other cancers, the death rate is still rising. Kidney cancer occurs most commonly in people 50–80 years of age. Men are more frequently affected than women; the male-to-female ratio is 5:3. It is the seventh most common cancer in men and tenth most common cancer in women in the UK.