Women who take aspirin on a regular basis cut their risk of developing the most common type of lung cancer by more than half, scientists have claimed.

The study, involving more than 14,000 women, suggested the drug's anti-inflammatory effects reduce the chances of developing any form of lung cancer by a third.

The US team said that not smoking is still the best protection against the disease.

100 years of aspirin: click here for a guide.

But they said aspirin, already widely used for the prevention and treatment of heart disease and arthritis, offers substantial benefits.

In a second study published in the British Journal of Cancer, experts predicted lung cancer deaths in the UK will fall significantly over the next five years, as more people stop smoking.

Bowel cancer

The New York-based research team compared 81women who developed lung cancer with 808 who had not, and looked at whether they used aspirin.

Not smoking is by far the best way to avoid lung cancer

Dr Arslan Akhmedkhanov

It was found that those who had taken aspirin three or more times a week for at least six months were "substantially" less likely to develop cancer.

The risk of developing any type of the disease was cut by a third, while the risk of non-small cell lung cancer - which accounts for about three quarters of cases - was reduced by more than half.

Further research is examining whether aspirin can help reduce the risk of bowel cancer and there is already some evidence it could protect against oesophageal cancer.

'Remarkable'

Dr Arslan Akhmedkhanov, who led the study at New York University's School of Medicine, said: "Not smoking is by far the best way to avoid lung cancer, but our study suggests that regular aspirin use could also confer some degree of protection against the disease."

He said further research was needed to confirm the study's findings.

Professor Gordon McVie, director general of Cancer Research UK, which owns the British Journal of Cancer, said: "Aspirin is a remarkable drug with a wide range of health benefits, and this is the latest evidence to suggest that it could become a useful weapon against cancer.

"But as much as these results are encouraging, people shouldn't fool themselves into thinking that taking aspirin somehow counteracts the dangers of smoking.

"Everything else pales into insignificance compared with the lethal effects of tobacco."

'Getting the message across'

A second study, published in the British Journal of Cancer, predicts UK death rates from lung cancer in under 75s will fall by 20% in men and 8% in women over the next five years.

Across Europe the anti-smoking message doesn't seem to be getting across

Dr Paul Brennan

Deaths in under 55s are set to fall more sharply - by 26% in men and 15% in women - because of drops in the numbers smoking.

But the analysis of 20 countries, by the International Agency for Research on Cancer, found other European countries are set to fare less well, as both smoking and lung cancer rates remain high.

Dr Paul Brennan, who led the research, said: "Health campaigns in the UK have been extremely successful at persuading people, particularly men, to kick the habit, and as a result deaths from lung cancer are starting to come down.

"But sadly, across Europe the anti-smoking message doesn't seem to be getting across.

Professor McVie said although there was good news about UK smoking habits, people should not be complacent.

"Young women in particular are seemingly immune to anti-smoking campaigns and we need to find new ways of getting the message across. "