Forty-three per cent of smokers in England tried to give up in 2007, reducing their likelihood of needing cancer treatment in the future, new figures show.
Professor Robert West, director of tobacco studies at the charity Cancer Research UK, presented his findings at a conference of Action on Smoking and Health (Ash) Wales.
His research analysed 27,000 smokers and ex-smokers between November 2006 and January 2008 and found that a vast number had tried to give up during that period.
The professor described the findings as "very encouraging", adding: "It can take many attempts to stop smoking for good, but the more times you try, the more likely you are to succeed in the end."
The charity's head of tobacco control, Elspeth Lee, agreed that the findings were promising and pointed out that smoking is "the single biggest preventable cause of cancer, killing thousands of people prematurely every year".
According to the research, half of wannabe quitters tried methods such as nicotine replacement therapy (NRT), with over-the-counter gums and patches providing particularly popular.