Revealed: the genes that make some smokers more prone to cancer

Scientists have identified for the first time genetic variations that increase the risk of lung cancer in people who smoke.

The finding shows that some people have an inherited susceptibility to the cancer, which makes them more vulnerable to the damaging effects of tobacco. The genetic variations are widespread, affecting up to half the population, and increase the risk of lung cancer in smokers by up to 80 per cent.

But scientists stressed yesterday that the discovery did not amount to a "licence to smoke" for people free of the genetic variants. The risk of lung cancer remains high in all smokers, regardless of their genetic make-up. The finding could allow stop-smoking services to be targeted at those at highest risk, who have a one-in-four chance of developing lung cancer. Those without the gene variants who smoke have about a one-in-seven chance.

Three separate research groups – in Britain, France and Iceland – which used newly developed methods to scan the human genome independently reached the same conclusion, strengthening confidence in their results. The findings are published in Nature and Nature Genetics.

More than one million cases of lung cancer are diagnosed each year worldwide and it is the most common cause of cancer-related deaths. In Britain, there are more than 38,000 new cases annually, and 33,000 deaths. Nine out of 10 cases in Britain are caused by smoking. Smokers are 26 times more likely to develop the disease than non-smokers.

By comparing the frequency of more than 300,000 gene variants in thousands of lung cancer patients, the three research groups narrowed the search down to two genetic variants on chromosome 15. Smokers with one copy of the two variants – present in half the population – have a 30 per cent increased risk of lung cancer, and those with two copies – one in 10 of the population – have an 80 per cent increased risk, compared with smokers without the variants.

But the underlying risk of developing lung cancer is already very high in smokers. In non-smokers, in whom the risk of lung cancer is less than 1 per cent, the presence or absence of the gene variants appears to make no difference (though one study suggested they might have an impact), implying that the genes are switched on by nicotine or other constituents of tobacco smoke.

Paul Brennan, of the International Agency for Research on Cancer in Lyons, France, who led one of the studies, said: "What is important for the individual is the absolute risk of getting lung cancer. If you smoke all your life it is about 15 per cent, and if you have no copies of the gene variants it will be a bit less. But if you have two copies it will be closer to 25 per cent. Obviously, even in those who have no copies there is still a very high risk of lung cancer in those who smoke."

The use of genome scanning techniques has already yielded new insights into the genetics of breast and bowel cancer, but this is the first time it has been used in lung cancer. Dr Brennan said the main benefit of the research lay in increasing understanding of the disease, not in identifying vulnerable smokers. "This gives us information about how cancer develops, which provides a target for pharmaceutical companies to develop new treatments," he added.

Suggested Topics
Life and Style
love + sex A new study has revealed the average size - but does that leave men outside the 'normal' range being thought of as 'abnormal'?
Arts and Entertainment
TV
Voices
The Palace of Westminster is falling down, according to John Bercow
voices..says Matthew Norman
Sport
Steve Bruce and Gus Poyet clash
football
Life and Style
ebookNow available in paperback
ebooks
ebookPart of The Independent’s new eBook series The Great Composers
News
Graham Norton said Irish broadcaster RTE’s decision to settle was ‘moronic’
TV
Arts and Entertainment
Jake and Dinos Chapman were motivated by revenge to make 'Bring me the Head of Franco Toselli! '
arts + ents Shapero Modern Gallery to show explicit Chapman Brothers film
Arts and Entertainment
Kurt Cobain performing for 'MTV Unplugged' in New York, shortly before his death
music Brett Morgen's 'Cobain: Montage of Heck' debunks many of the myths
Life and Style
life
Sport
Brendan Rodgers
football The Liverpool manager will be the first option after Pep Guardiola
News
Amazon misled consumers about subscription fees, the ASA has ruled
news
Arts and Entertainment
Myanna Buring, Julian Rhind-Tutt and Russell Tovey in 'Banished'
TV Jimmy McGovern tackles 18th-century crime and punishment
Arts and Entertainment
Paul Whitehouse as Herbert
arts + ents
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Recruitment Genius: Lettings and Sales Negotiator - OTE £46,000

    £16000 - £46000 per annum: Recruitment Genius: This is an opportunity to join ...

    Recruitment Genius: Home Care Worker - Reading and Surrounding Areas

    £9 - £13 per hour: Recruitment Genius: This is a great opportunity to join a s...

    Recruitment Genius: Key Sales Account Manager - OTE £35,000

    £25000 - £35000 per annum: Recruitment Genius: Have you got a proven track rec...

    Recruitment Genius: Sales Executive - OTE £40,000

    £15000 - £18000 per annum: Recruitment Genius: This is a great opportunity for...

    Day In a Page

    Syrian conflict is the world's first 'climate change war', say scientists, but it won't be the last one

    Climate change key in Syrian conflict

    And it will trigger more war in future
    How I outwitted the Gestapo

    How I outwitted the Gestapo

    My life as a Jew in wartime Berlin
    The nation's favourite animal revealed

    The nation's favourite animal revealed

    Women like cuddly creatures whilst men like creepy-crawlies
    Is this the way to get young people to vote?

    Getting young people to vote

    From #VOTESELFISH to Bite the Ballot
    Poldark star Heida Reed: 'I don't think a single bodice gets ripped'

    Poldark star Heida Reed

    'I don't think a single bodice gets ripped'
    The difference between America and Israel? There isn’t one

    The difference between America and Israel? There isn’t one

    Netanyahu knows he can get away with anything in America, says Robert Fisk
    Families clubbing together to build their own affordable accommodation

    Do It Yourself approach to securing a new house

    Community land trusts marking a new trend for taking the initiative away from developers
    Head of WWF UK: We didn’t send Cameron to the Arctic to see green ideas freeze

    David Nussbaum: We didn’t send Cameron to the Arctic to see green ideas freeze

    The head of WWF UK remains sanguine despite the Government’s failure to live up to its pledges on the environment
    Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

    Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

    Set in a mythologised 5th-century Britain, ‘The Buried Giant’ is a strange beast
    With money, corruption and drugs, this monk fears Buddhism in Thailand is a ‘poisoned fruit’

    Money, corruption and drugs

    The monk who fears Buddhism in Thailand is a ‘poisoned fruit’
    America's first slavery museum established at Django Unchained plantation - 150 years after slavery outlawed

    150 years after it was outlawed...

    ... America's first slavery museum is established in Louisiana
    Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

    Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

    The first 'American Idol' winner on how she manages to remain her own woman – Jane Austen fascination and all
    Tony Oursler on exploring our uneasy relationship with technology with his new show

    You won't believe your eyes

    Tony Oursler's new show explores our uneasy relationship with technology. He's one of a growing number of artists with that preoccupation
    Ian Herbert: Peter Moores must go. He should never have been brought back to fail again

    Moores must go. He should never have been brought back to fail again

    The England coach leaves players to find solutions - which makes you wonder where he adds value, says Ian Herbert
    War with Isis: Fears that the looming battle for Mosul will unleash 'a million refugees'

    The battle for Mosul will unleash 'a million refugees'

    Aid agencies prepare for vast exodus following planned Iraqi offensive against the Isis-held city, reports Patrick Cockburn