About 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 the tiny tubes found in the nephrons. (The nephrons are the tiny parts of the kidney that filter blood and form urine.)

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, bones or brain.

Learn more about:

• Subtypes of renal cell carcinoma (RCC)
• Other types of kidney cancer
• The kidneys
• What causes kidney cancer?
• Who gets kidney cancer?

Subtypes 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. It is also known as upper tract urothelial cancer.

For more on this, see Upper Tract Urothelial Cancer.

Wilms tumour (nephroblastoma)

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

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

Secondary cancer

Very rarely, cancer can spread from a primary cancer somewhere else in the body to the kidney. This is known as secondary cancer (metastasis). This secondary cancer is not kidney cancer and it behaves more like the primary cancer.

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

The kidneys

The kidneys are two bean-shaped organs, each about the size of a fist. They are found deep inside your abdomen (belly), positioned near the middle of your back, on either side of the spine.

The kidneys are part of the body’s urinary system, which also includes the:

• ureters – tubes that take urine from the kidneys to the bladder
• bladder – a hollow sac that stores urine (wee) until you need to urinate
• urethra – a tube that takes urine from the bladder to outside the body.

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.

What the kidneys do

Filter blood – The main role of the kidneys is to filter and clean the blood. Blood flows through the renal artery into each kidney, where it is filtered through tiny networks of tubes called nephrons. The clean blood then flows out through the renal vein to the rest of the body.

Make urine – When the kidneys filter the blood, they remove excess water and waste products to make urine (wee or pee). The urine collects in an area of each kidney called the renal pelvis, and then flows through the ureters into the bladder.

Produce hormones – 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.

The urinary system

What causes kidney cancer?

The exact cause of kidney cancer is not known. Research shows that people with certain risk factors are more likely to develop kidney cancer. Having a risk factor does not mean you will develop kidney cancer, and some people develop kidney cancer without having any known risk factors. If you are concerned, talk to your doctor.

Risk factors for kidney cancer include:

• smoking – people who smoke have almost twice the risk of developing kidney cancer as those who don’t smoke. About 1 in 3 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, hereditary leiomyomatosis RCC, tuberous sclerosis, and Lynch syndrome.

Who gets kidney cancer?

Each year about 4500 Australians are diagnosed with kidney cancer. Men are twice as likely as women to be diagnosed with kidney cancer. It is the sixth most common cancer in men and the tenth most common cancer in women (excluding non-melanoma skin cancers). It is more common in people over 50, but it can occur at any age.

→ READ MORE: Kidney cancer symptoms