What is kidney cancer?
Kidney or ‘renal’ cancer is a malignant growth of the cells of the kidney. There are two kidneys, they lay each side of the midline on the back wall of the upper abdominal cavity. The normal function of the kidney is to filter waste products from the blood. The kidney excretes these waste products and water into the ‘renal pelvis’ the central collecting system in the kidney. The mixture of water and waste products is ‘urine’. Urine travels down the ureter into the bladder where it is stored.
There are several types of kidney cancer which are best divided into two groups:
Renal cell cancers
These are cancers of the cells which make up the ‘meat’ of the kidney, sometimes called hypernephromas. 85% of kidney cancers are this type, they are adenocarcinomas. They can be split into two subgroups of clear cell and granular cell carcinomas. Some cancers are mixed clear cell and granular cell carcinomas.
Transitional cell cancers of the renal pelvis and the ureter
These are cancers of the cells lining the inside of the collecting system of the kidney and the ureter and make up 7% of kidney cancers. They are the same type as transitional cell cancers of the bladder. 30 to 50% of people with this type of kidney cancer go on to develop bladder cancer at a later date.
Note: This guidance does not cover Wilms tumour (a type of kidney cancer) and any such cases in adults must be discussed with Medical Services.
Kidney cancer affects almost 6000 people a year in the UK and each year about 2500 people die of kidney cancer. 5 year survival is around 40%. Men are more commonly affected then women. The risk is increased by smoking, long term use of some drugs, obesity and working with heavy metals and solvents. It is rare under the age of 50. The risk is increased in certain genetic syndromes including:
- Von-Hippel-Lindau (VHL) Syndrome
- Tuberous Sclerosis
- Birt-Hogg-Dube Syndrome
- Hereditary non-VHL clear cell renal cell cancer
- Hereditary papillary renal cell cancer
People with these syndromes are more likely to be affected at a young age and to have tumours in both kidneys. They may also have other disabilities related to their underlying condition.
Amended October 2011