Kidney cancer

Kidney cancer is cancer that starts in the cells of the kidney.

About 9 out of 10 kidney cancers are renal cell carcinoma (RCC), sometimes called renal cell adenocarcinoma. RCCs start in the cells lining tiny tubes in the kidney’s nephrons. This information is about RCC.

In the early stages of RCC, the tumour is in the kidney only. Usually one kidney is affected, but in rare cases there is a tumour in both kidneys.

As the cancer grows, it can spread to areas near the kidney, such as the surrounding fatty tissue, veins, adrenal glands, lymph nodes, ureters or the liver. It may also spread to other parts of the body, such as the lungs or bones.

Learn more about:

• The kidneys
• The different types of renal cell carcinoma
• Other types of kidney cancer
• What causes kidney cancer?
• Who gets kidney cancer?

The kidneys

The kidneys are two bean-shaped organs, each about the size of a fist. They are deep inside your abdomen, positioned near the middle of your back, on either side of the spine. The kidneys are part of the body’s urinary system.

What the kidneys do

The main role of the kidneys is to filter and clean the blood.

Blood flows into each kidney through the renal artery and is filtered through tiny networks of tubes called nephrons. The clean blood then goes back into the rest of the body through the renal vein.

When the kidneys filter the blood, they remove excess water and waste products and turn these into urine (wee or pee). Urine travels from each kidney into a funnel called the renal pelvis, then through a long, thin tube called the ureter, and into the bladder.

Urine is stored in the bladder until you need to urinate, when it leaves the body through a tube called the urethra. In females, the urethra is a short tube in front of the vagina. In males, the tube is longer and passes through the prostate and penis.

Hormone production

The kidneys also help your body control how much blood it needs. They do this by making hormones that regulate blood pressure and trigger the production of red blood cells.

What the adrenal glands do

An adrenal gland sits above each kidney. The adrenal glands produce a number of hormones. Although these glands are not part of the urinary system, kidney cancer can sometimes spread to them.

The urinary system

The different types of renal cell carcinoma (RCC)

There are several types of RCC, based on the way the cells look under a microscope. The most common type is clear cell renal cell carcinoma.

Other types of kidney cancer

RCC is the most common type of kidney cancer, but there are other less common types:

Urothelial carcinoma (or transitional cell carcinoma)

This can begin in the ureter or in the renal pelvis, where the kidney and ureter meet. Urothelial carcinoma of the kidney or ureter behaves and is treated like bladder cancer (another type of urothelial cancer), rather than like RCC.

For more on this, see Bladder cancer.

Wilms tumour (nephroblastoma)

This is the most common type of kidney cancer in younger children, but it is still rare.

For more on this, see childrenscancer.canceraustralia.gov.au.

Secondary cancer

Very rarely, cancer in the kidney can be a secondary cancer (metastasis) from a primary cancer located in another part of the body. However, this type of cancer is not kidney cancer and it behaves more like the original cancer.

For more on this, see our information on the type of primary cancer diagnosed.

What causes kidney cancer?

The factors listed below may increase the risk of a person developing kidney cancer. However, having one or more of these risk factors does not mean you will develop cancer.

• Smoking – people who smoke have almost twice the risk of developing kidney cancer as nonsmokers. About 1 in 3 cases of all kidney cancers are thought to be related to smoking; the longer a person smokes and the more they smoke, the greater the risk.
• Obesity – too much body fat may cause changes to some hormones that can lead to kidney cancer.
• High blood pressure – whatever the cause, high blood pressure increases the risk of kidney cancer.
• Kidney failure – people with end-stage kidney disease have a higher risk of developing kidney cancer.
• Family history – people with a parent, brother or sister (first-degree relative) with kidney cancer are at increased risk.
• Inherited conditions – about 2–3% of kidney cancers develop in people who have particular inherited syndromes, including von Hippel–Lindau disease, hereditary papillary RCC, Birt–Hogg–Dubé syndrome and Lynch syndrome.
• Exposure to toxic substances at work – the risk may be higher after regular exposure to chemicals, such as some metal degreasers, arsenic or cadmium, which are used in mining, farming, welding and painting.

Who gets kidney cancer?

More than 3000 people are diagnosed with kidney cancer in Australia each year. It makes up about 2.5% of all cancers. It is twice as common in men than women, and is the ninth most diagnosed cancer for Australian men. The risk of kidney cancer increases with age, and most cases occur in people over 50.