Fewer people die of lung cancer in Britain than anywhere else in the world, according to top Oxford scientists.

Sir Richard Doll, of the Imperial Cancer Research Fund, believes the chief reason for the good news is because smokers are quitting cigarettes.

His research, comparing the smoking habits of 982 lung cancer patients and 3,185 not suffering from illness, shows death through the disease has halved in the last 50 years.

He also claims that 16 per cent of men who continue to light up will die from lung cancer before the age of 75.

But for those who quit at the age of 50 the risk is only six per cent, while those who give up tobacco at 30 reduce the risk to four per cent.

Sir Richard, 87, became famous in 1950 when he was the first scientist to link lung cancer to smoking.

He said: "Our 1950 study showed that smoking was a cause of most of the lung cancer in Britain at that time, and our new study shows that widespread cessation of smoking has halved the number of lung cancer deaths that would otherwise be occurring in Britain in the year 2000." The new study, which will be published in Friday's British Medical Journal, backs up his initial research, which has gauged how giving up cigarettes increases a person's chances of steering clear from lung cancer.

While Britain's lung cancer victims made up the largest number anywhere in the world in 1950, they are now the smallest. But Sir Richard, who wrote the report with his colleague, Prof Sir Richard Peto, said smoking was still the biggest cause of premature death in Britain.

Prof Peto said: "There are still ten million smokers in Britain, and about five million will be killed by tobacco if they don't stop.