There are two major types of cancer affecting the kidneys in adults.

Renal cell cancer (also known as hypernephroma)
This is cancer that arises from the main body of the kidney. It's not known what causes the normal kidney cells to undergo malignant change although it can occur in certain rare hereditary conditions.

Transitional cell cancer
This is cancer arising from within the drainage system of the kidney (pelvis and ureter). It is the same cancer type as that commonly found in the bladder. The two main risk factors for this type of cancer are cigarette smoking and kidney damage arising from prolonged use of non-steroidal anti-inflammatory painkillers (NSAIDs) (called analgesic nephropathy).

Both cancers rarely appear before the age of 50 and they become more common with age. They are two to three times more common in men than women.