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
Arts and Entertainment
'New Tricks' star Dennis Waterman is departing from the show after he completes filming on two more episodes
tvOnly remaining original cast-member to leave crime series
Frank Lampard and his non-celebration
premier leagueManchester City vs Chelsea match report from the Etihad Stadium
Esteban Cambiasso makes it 3-3
premier league
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
Mario Balotelli celebrates his first Liverpool goal
premier leagueLiverpool striker expressed his opinion about the 5-3 thriller with Leicester - then this happened
people'I hated him during those times'
Britain's shadow chancellor Ed Balls (L) challenges reporter Rob Merrick for the ball during the Labour Party versus the media soccer match,
peopleReporter left bleeding after tackle from shadow Chancellor in annual political football match
Arts and Entertainment
Female fans want more explicit male sex in Game of Thrones, George R R Martin says
tvSpoiler warning: Star of George RR Martin's hit series says viewers have 'not seen the last' of him/her
Dame Vivienne Westwood has been raging pretty much all of her life
peopleFirst memoir extracts show she 'felt pressured' into going out with the Sex Pistols manager
Arts and Entertainment
Lauryn Hill performing at the O2 Brixton Academy last night
musicSinger was more than 90 minutes late
Lewis Hamilton in action during the Singapore Grand Prix
Formula OneNico Rosberg retires after 14 laps
Rumer was diagnosed with bipolarity, attention deficit hyperactivity disorder and post-traumatic stress disorder: 'I was convinced it was a misdiagnosis'
peopleHer debut album caused her post-traumatic stress - how will she cope as she releases her third record?
Arts and Entertainment
tvReview: 'Time Heist' sees a darker side to Peter Capaldi's Doctor
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating

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

    iJobs Job Widget
    iJobs General

    Head of Marketing and Communications - London - up to £80,000

    £70000 - £80000 per annum: Ashdown Group: Group Head of Marketing and Communic...

    Nursery Nurse

    Negotiable: Randstad Education Manchester: Level 3 Nursery Nurse required for ...

    Nursery Nurse

    Negotiable: Randstad Education Manchester: L3 Nursery Nurses urgently required...

    SEN Teaching Assistant

    Negotiable: Randstad Education Manchester: We have a number of schools based S...

    Day In a Page

    Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

    Despite the result, this is the end of the status quo

    Boyd Tonkin on the fall-out from the Scottish referendum
    Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

    Manolo Blahnik: Flats, Englishness, and Mary Beard

    The shoe designer who has been dubbed 'the patron saint of the stiletto'
    The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

    Scrambled eggs and LSD

    Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
    'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

    'Normcore': Blending in is the new standing out

    Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
    Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

    New leading ladies of dance fight back

    How female vocalists are now writing their own hits
    Mystery of the Ground Zero wedding photo

    A shot in the dark

    Mystery of the wedding photo from Ground Zero
    His life, the universe and everything

    His life, the universe and everything

    New biography sheds light on comic genius of Douglas Adams
    Save us from small screen superheroes

    Save us from small screen superheroes

    Shows like Agents of S.H.I.E.L.D are little more than marketing tools
    Reach for the skies

    Reach for the skies

    From pools to football pitches, rooftop living is looking up
    These are the 12 best hotel spas in the UK

    12 best hotel spas in the UK

    Some hotels go all out on facilities; others stand out for the sheer quality of treatments
    These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

    Widespread fear of Isis is producing strange bedfellows

    Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
    Topshop goes part Athena poster, part last spring Prada

    Topshop goes part Athena poster, part last spring Prada

    Shoppers don't come to Topshop for the unique
    How to make a Lego masterpiece

    How to make a Lego masterpiece

    Toy breaks out of the nursery and heads for the gallery
    Meet the ‘Endies’ – city dwellers who are too poor to have fun

    Meet the ‘Endies’ – city dwellers who are too poor to have fun

    Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
    Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

    Ian Paisley’s decision to make peace with his IRA enemies

    His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam