The number of cases of kidney cancer diagnosed each year in Great Britain has risen over 9,000 for the first time, new figures from Cancer Research UK show today.
Experts believe that obesity could be one of the key factors behind the staggering 135 per cent rise in kidney cancer rates over the last 35 years.
In 1975 there were almost 3,000 cases of the disease and it was the 14th most common cancer in Britain, but the numbers have been steadily rising in Britain since the mid-70s.
And the latest figures show that the number of cases is just over 9,000 - making it the eighth most common cancer in Britain.
Professor Tim Eisen, a Cancer Research UK kidney cancer expert, based at the University of Cambridge, said: "Over the last 10 years, Cancer Research UK has helped to develop new drugs which destroy the blood supply to the kidney cancers. These drugs control the disease in most patients but do not cure it.
"It is best to prevent the problem in the first place - maintaining a healthy weight and not smoking are the best ways of doing that.
"The other important point is to see your doctor if you have noticed blood in your urine as this can be an early sign of something wrong. If the kidney cancer is caught early, it can often be cured by surgery."
Some, but not all, of this increase is believed to be down to more widespread use of imaging techniques which have helped diagnose more kidney tumours.
But evidence from other studies shows there has also been a rise in the number of advanced kidney cancer cases detected - suggesting other factors are also in play.
After smoking, obesity is one of the main risk factors for kidney cancer - it increases the risk of the disease by 70 per cent.
Cancer Research UK figures estimate that about a quarter of kidney cancer cases in men and 22 per cent in women are linked to being overweight. Overweight people produce higher levels of certain hormones than people of a healthy weight and this can contribute to an increased risk of several types of cancer including kidney.
While smoking rates in the UK have fallen over the last 35 years, obesity is on the rise. In the UK, figures show that nearly 70 per cent of men and almost 60 per cent of women have a BMI of 25 or more - classed as overweight.
Newscaster Nicholas Owen, who is a kidney cancer survivor, said: "It's worrying to see the number of cases rise. But it is so important for people to go to their doctor if they experience any symptoms like blood in urine. The chances are it won't be cancer, but if it is, spotting it early means that treatment is often easier and many more people survive."
Sara Hiom, director of information at Cancer Research UK, said: "Too few people know about the significant cancer risks associated with being very overweight. While giving up smoking remains the best way to cut your chances of developing kidney cancer, the importance of keeping a healthy weight shouldn't be overlooked.
"Obesity is not only linked to kidney cancer but six other types of cancer and other diseases as well.
"Kidney cancer survival rates have greatly improved over the last 35 years thanks to research funded by our generous supporters. To ensure we continue to make progress, it's really important that the disease is diagnosed as early as possible to give patients the best treatment options.
"Cancer Research UK is working with partners to raise awareness of blood in urine as a possible sign of kidney and bladder cancer and encourage people with this symptom to go to their doctor as quickly as possible."
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