Kidney cancer is at its highest level and researchers blame obesity for this.

Researchers from Cancer Research UK and the University of Cambridge have discovered that the number of people diagnosed with kidney cancer has increased drastically - from 3,000 in 1975 to 9,000 in 2009.

Attributing the sharp spike to increasing obesity, researchers say obesity raises the risk of cancer by 70 per cent. They have found that more than 25 per cent of men and 22 per cent of women get the cancer because of being overweight.

Obese or overweight people produce higher levels of hormones which can cause cancer. In 2009, almost a quarter of adults in England were obese. A further 44 per cent of men and 33 per cent of women were overweight, according to Press Association.

Tim Eisen, professor at the University of Cambridge, said the focus must be on prevention. According to him, the best way of doing this is maintaining a healthy weight and not smoking. Another 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 detected early, it can often be cured by surgery," Press Association quoted Eisen as saying.

Nicholas Owen, BBC newscaster and kidney cancer survivor, was quoted as saying: "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."