In the UK, kidney, or renal cancer is the fifth most common cancer in men and the 10th most common cancer in women. There are more than 33 cases diagnosed every day.
Since the late 1970s, kidney cancer incidence rates have more than doubled in the UK with the largest increase in women.
Half of all kidney cancer cases in the UK each year are diagnosed in people aged 70 and over and it is more common in people living in the most deprived areas.
Small kidney cancers do not usually cause symptoms. They are often diagnosed by chance when people are having tests or scans for some other reason. When kidney cancer does cause symptoms these may include:
Blood in the urine
This is the most common symptom, if you ever have blood in your urine – even if you notice it just once – visit your GP, so that the cause can be investigated. The earlier a cancer is picked up, the easier it is to treat it and the more likely the treatment is to be successful. So it is important that you go to your GP as soon as possible if you notice worrying symptoms.
Other symptoms may include:
- A dull pain in your back on one side (below the ribs) that won't go away
- A high temperature, night sweats and feeling very tired
- Losing weight for no obvious reason
- A lump in the tummy area, side or back.
- Loss of appetite
- Swelling of the veins in the testicles
- A general feeling of poor health
- High blood pressure and having fewer red blood cells than normal (anaemia) may also be symptoms of kidney cancer.
See your GP immediately if you have pain or a swelling or lump in your kidney area (on either side of your body, just below your ribcage).
Most people who go to the doctor with blood in their urine do not have kidney cancer but a doctor should always investigate blood in the urine. As the bleeding can come and go you may make the mistake of thinking that the problem has gone away. This can mean that an early, treatable cancer is allowed to grow to a stage where it may be more difficult to treat.
The exact cause of kidney cancer is unknown, but there are risk factors that can increase the chances of developing the condition.
The three main risk factors for kidney cancer are:
Obesity is a significant risk factor for kidney cancer.
A study carried out by Cancer Research UK in 2011 found that around a quarter of kidney cancer cases are associated with being overweight or obese (25% of cases in men and 22% in women).
There's a strong link between someone’s body mass index (BMI) and their risk of developing kidney cancer. A BMI score of 25 or above has been shown to increase a person's chances of developing kidney cancer. Those with a BMI score of 30 or above are at particularly high risk. Cases of kidney cancer have been increasing over the last 40 years, which has been linked to the rising obesity levels.
Smoking is a significant risk factor for developing kidney cancer, the more you smoke the greater the risk. For example, research has shown that if you regularly smoke 10 cigarettes a day, you're one-and-a-half times more likely to develop kidney cancer compared to a non-smoker. This increases to twice as likely if you smoke 20 or more cigarettes a day.
Family history and genetics
If you have a close family member (parents, brothers, sisters or a child) who's been diagnosed with kidney cancer, you're about twice as likely to develop kidney cancer yourself. A small number of people inherit faulty genes that increase their risk of developing 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.
Other possible risk factors
- Mild painkillers – some mild painkillers have been linked to an increased risk of developing kidney cancer; NSAIDs, such as ibuprofen, may slightly increase the risk, although occasional use or low doses are unlikely to be harmful.
- Kidney disease – if you have kidney failure and need to have regular dialysis (treatment to replicate the functions of the kidneys), your risk of developing kidney cysts and kidney cancer is increased
- High blood pressure (hypertension) – high blood pressure is a known risk factor for kidney disease.