Find out what causes kidney cancer and how you could reduce your risk of getting it.
We don't know what causes most kidney cancer. But some factors may increase your risk of getting it.
What a risk factor is
Anything that can increase your risk of getting a disease is called a risk factor.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.
Risk factors for kidney cancer
Being very overweight (obese) increases the risk of getting kidney cancer. It causes around a quarter of kidney cancers (25% in men and 22% in women).
Obese means that your body mass index (BMI) is 30 or higher. More roughly, this means that your weight is at least 25% higher than the top of the healthy range for your height. Your BMI is worked out by comparing your height and weight.
Being overweight causes changes in hormones in the body, particularly for women. It could be this change in the body’s hormone balance that increases the risk of kidney cancer.
If you smoke, your risk of getting kidney cancer goes up.
On average, smokers have a 50% increase in risk. But the risk increases with the number of cigarettes that you smoke.
People who smoke more than 20 cigarettes a day have up to double the risk of the most common type of kidney cancer (renal cell cancer) compared to non smokers.
Smokers also have up to 3 times the risk of developing cancer of the central area of the kidney (the renal pelvis) compared to non smokers. But your risk falls if you stop smoking. After 10 years it becomes the same as any other non smoker.
People with kidney failure have their blood filtered by a machine about twice a week. This is called dialysis.
People having long term kidney dialysis have an increased risk of developing kidney cysts. This increases the risk of kidney cancer.
The longer you have dialysis, the greater your risk of kidney cancer. But this is probably because you needed dialysis due to kidney disease. The dialysis itself is not directly related to the cancer risk.
A few people inherit faulty genes that increase their risk of developing kidney cancer. Cancers caused by these faulty genes are called hereditary or familial kidney cancer.
Changes in the DNA that makes up the faulty gene make it behave in an abnormal way. Scientists are finding out which genes carry these mistakes in the DNA. In the future this could help doctors predict who is at risk of getting hereditary kidney cancer.
People with kidney cancer who have these genetic conditions often have cancer in both kidneys (bilateral kidney cancer). They may also have several tumours in each kidney. They often develop the cancer at a younger age than people with non inherited cancers.
Inherited conditions that increase the risk of kidney cancer
Von Hippel-Lindau (VHL) syndrome
This is an inherited cancer syndrome. The Von Hippel-Lindau (VHL) gene runs through affected families.
People who carry the gene have an increased risk of developing several quite rare cancers in the brain, spine, pancreas, eyes and inner ear. About 40 out of 100 (40%) of people with VHL get kidney cancer.
This is another condition caused by a faulty gene. People with tuberous sclerosis have an increased risk of kidney cysts and kidney cancer.
About 33 out of 100 (33%) cases are inherited. The other 66 out of 100 (66%) occur because the gene has changed (mutated) in those people for the first time.
It can cause skin, brain and heart problems, as well as kidney disease.
This inherited condition causes many non cancerous (benign) tumours to develop in the hair follicles of the skin. These usually develop on the face, neck and trunk. People who carry this gene have an increased risk of kidney cancer.
Hereditary clear cell and papillary renal cell cancer
Hereditary clear cell kidney cancer and hereditary papillary kidney cancers are both caused by inherited faulty genes. They are dominant genetic conditions. This means that you only have to inherit the faulty gene from one parent. Even so, they are both very rare.
People with a first degree relative who have been diagnosed with kidney cancer have roughly double the risk of developing renal cell carcinoma themselves. A first degree relative is your parent, brother or sister, or child.
Some research studies have found a link between high blood pressure or high blood pressure medicines and kidney cancer.
It is likely that high blood pressure is the link, rather than the medicines. High blood pressure is a known risk factor for kidney disease in general.
The risk of kidney cancer is slightly lower in people who drink alcohol compared to non drinkers. But alcohol increases the risk of several other types of cancer.
People who have had thyroid cancer have a risk of kidney cancer that is 2 to 7 times higher than people who have not had thyroid cancer. This may be due to gene changes that are common to both cancers.
Two large studies have found that people with diabetes have a higher risk of kidney cancer.
The risk may be higher in people who use insulin to control their diabetes. But other diabetic medicines such as metformin or pioglitazone don't seem to increase the risk.
Men treated with radiotherapy for testicular cancer have double the risk of kidney cancer compared to men in the general population. But the risk is still small. It rises and after 30 years is increased by almost three times.
Women who have had radiotherapy for cancer of the neck of the womb (cervical cancer) have their risk of kidney cancer increased by almost a third. After 30 years the risk is almost double compared to that of women in the general population.
There is limited evidence that removal of the womb (hysterectomy) may slightly increase the risk of kidney cancer. Researchers are looking into the reason for this small increase. It may be linked with use of hormone replacement therapy by these women, physical changes after surgery, or conditions which led to women having a hysterectomy.
Some mild painkilling drugs have been linked to increased kidney cancer risk.
One drug that could definitely increase the risk was phenacetin, but this has been taken off the market in the UK.
Some other types of painkillers called non steroidal anti inflammatory drugs (NSAIDs) may increase the risk of kidney cancer slightly. These include ibuprofen. Occasional or low dose use is unlikely to be harmful.
Other possible causes
Stories about potential causes of cancer are often in the media. It isn’t always clear which ideas are supported by good evidence.
You might hear about possible causes we haven’t included here. This is because there is no evidence about them or because the evidence isn’t clear.