Review puts merits of breast cancer screening under the microscope

The success of the national breast screening programme which offers tests to almost two million women a year has been called into question by a review which says it is harming almost as many women as it helps and must be urgently re-evaluated.

The benefits of breast screening – early detection of cancer followed by rapid treatment – are finely balanced against the harms of overdiagnosis followed by unnecessary treatment and suffering, and have never been properly weighed against each other, the review by a leading epidemiologist says.

The stark conclusions mark a new phase in the war over breast screening, which has divided the medical establishment for more than 20 years. But they also raise questions about all screening programmes, including those for bowel, prostate and cervical cancers, which similarly bring harm as well as benefit.

The central drawback of screening is that in some cases the cancer (or other disease) detected does not need treating, either because it is a false alarm, because it resolves naturally or because it is very slow growing (so you die of something else). In these cases, the only result of screening is that the individual spends more of their life living in the shadow of cancer, without living longer. They may be treated, and suffer pain and anxiety, to no avail.

Supporters of the national breast screening programme, which has been running since 1988 and offers mammography (x-ray examination of the breasts) to all women aged 50 to 70 (to be extended to ages 47 to 73 by 2012), say it prevents an estimated 1,400 deaths a year. They claim that breast screening saves two women's lives for every one who receives unnecessary treatment.

Critics dispute these figures, claiming that for every woman saved, as many as 10 undergo unnecessary treatment – which can include surgical removal of the breast (mastectomy) – and up to 500 have at least one false alarm, including in up to half the cases a biopsy (the removal of a sample of breast tissue).

The simmering dispute between the two sides boiled over last March, when the British Medical Journal published a paper on breast screening in Denmark which showed that deaths from breast cancer had fallen faster in areas without screening than in those where it was used.

It concluded that the decline in the breast cancer death rate was "more likely explained by changes in risk factors and improved treatment than by screening mammography".

The paper, the latest in a series by the Nordic Cochrane Centre to be critical of breast screening, provoked a blizzard of responses accusing the researchers of "undermining the trust of women" and the BMJ of "taking sides".

Stung by the accusations, Fi Godlee, editor of the BMJ, asked Professor Klim McPherson, public health epidemiologist of Oxford University, to review the evidence, and the results are published in the BMJ's current issue.

Professor McPherson, citing US evidence, says that breast screening reduces the death rate by 14 per cent in the under-60s, which is of "marginal statistical significance", and by 32 per cent in the under-70s. But even this is a small benefit because at age 60 the risk of death from breast cancer over the next 15 years is just 1.2 per cent – 259 women in the UK would have to be screened to avoid one death.

"Individual benefit from mammography is thus very small, but this is not widely understood. In part this is due to obfuscation from organisers of mammography services assuming that a positive emphasis is needed to ensure reasonable compliance," Professor McPherson says.

He calls for a "full examination of all the data" and more honesty from the NHS about the scientific uncertainties. He also suggests that the National Institute for Clinical Excellence (NICE) should review the evidence.

"There is no doubt that screening for breast cancer has limited benefit and some possibility of harm for an individual woman and is of marginal cost-effectiveness for the community... The NHS screening programme needs to be really clear about the uncertainties when communicating with women... More importantly we all need to understand better how a national programme of such importance could exist for so long with so many unanswered questions."

Ms Godlee said: "I don't think the public understands that screening carries both risks and benefits. Often doctors don't either – they are caught up by the notion that prevention is better than cure. If you are intervening with a healthy population in the hope you can make their lives better and longer then the burden of proof is much higher and the strength of the evidence you need greater."

She added: "The screening lobby thinks the BMJ has got a bee in its bonnet about screening. That is not the case – we follow the evidence. The Danish team [from the Nordic Cochrane Centre] do good work which is very thorough and of good quality. It is fair to say that we have not had the same quality of submissions from the other side. We would be delighted if someone came forward with a robust defence of the screening programme – I don't think they have done that."

Sarah Sellars, director of the NHS Breast Screening Programme said: "The vast majority of evidence from properly conducted research clearly shows that regular mammography reduces deaths from breast cancer. The World Health Organisation's International Agency for Research on Cancer (IARC) concluded that there is a 35 per cent reduction in mortality from breast cancer among regularly screened women aged 50-69 years old.

"There is a risk of overdiagnosis, and possible subsequent overtreatment, associated with any screening programme. But recent independent studies show the risk of overdiagnosis is very much lower than some other estimates have claimed, and that the benefits far outweigh the risks."

Pink and powerful

With its pink ribbons, fashion shows, fun runs and awareness months, the breast cancer lobby is one of the most powerful health movements in the country. It has raised the profile of Britain's number one cancer, funnelled millions into research and has vigorously promoted breast screening.

But it has also sparked accusations that it has drawn attention and funds from other cancers that are "less glamorous" but cause death and illness on a greater scale. Lung cancer claims more lives but principally affects older, working class, men who lack the pulling power of the glossy young women used to front the breast cancer campaigns.

Prostate cancer charities also complain that a disease that kills almost as many men – 10,000 a year – as women who die of breast cancer – 12,000 – receives a fraction of the research income and has consequently benefited from fewer advances in treatment.

In numbers...

45,000 new cases diagnosed each year

50 per cent rise in cases in the last 25 years

12,000 deaths a year

82 per cent of patients survive for five years

66 per cent of patients survive for 20 years

50 per cent of deaths are among women aged over 70

Death rates have fallen by a third since peaking in the late 1980s

The Government needs to study the data

Editorial, Viewspaper, page 2

VIDEO
Arts & Entertainment
Ricky Gervais at a screening of 'Muppets Most Wanted' in London last month
tvRicky Gervais on the return of 'Derek' – and why he still ignores his critics
Sport
Luis Suarez of Liverpool celebrates his goal
sport
Arts & Entertainment
Homer meets Lego Marge in the 25th anniversary episode of The Simpsons, set to air on 4 May
tv
Arts & Entertainment
James Franco and Chris O'Dowd in Of Mice and Men on Broadway
theatreReview: Of Mice and Men, Longacre Theatre
Life & Style
Infant child breast-feeding with eyes closed
healthTo stop mummy having any more babies, according to scientists
News
news
Life & Style
Going down: Google's ambition to build an elevator into space isn't likely to be fulfilled any time soon
techTechnology giant’s scientists say there is no material strong enough for a cable from Earth into orbit
Arts & Entertainment
film
News
David Cameron sings a hymn during the enthronement service of The Most Rev Justin Welby as Archbishop of Canterbury, at Canterbury Cathedral last year
news
Life & Style
From long to Jong: Guy Pewsey gets the North Korean leader's look
fashionThe Independent heads to an Ealing hairdressers to try out the North Korean dictator's trademark do
Extras
indybest10 best smartphones
Arts & Entertainment
tvCreator Vince Gilligan sheds light on alternate endings
Life & Style
Google Doodle celebrates the 63rd anniversary of the Peak District National Park
tech
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Have you tried new the Independent Digital Edition iPad app?

ES Rentals

    Independent Dating
    and  

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

    iJobs Job Widget
    iJobs General

    Apprentice IT Technician

    £150.00 per week: QA Apprenticeships: This company is a company that specializ...

    1st Line Technical Service Desk Analyst IT Apprentice

    £153.75 per week: QA Apprenticeships: This company is an innovative outsourcin...

    1st Line Helpdesk Engineer Apprentice

    £150.00 per week: QA Apprenticeships: This company has been providing on site ...

    Sales Associate Apprentice

    £150.00 per week: QA Apprenticeships: We've been supplying best of breed peopl...

    Day In a Page

    Ricky Gervais: 'People are waiting for me to fail. If you think it's awful, then just don't watch it'

    Ricky Gervais: 'People are waiting for me to fail'

    As the second series of his divisive sitcom 'Derek' hits screens, the comedian tells James Rampton why he'll never bow to the critics who habitually circle his work
    Mad Men series 7, TV review: The suits are still sharp, but Don Draper has lost his edge

    Mad Men returns for a final fling

    The suits are still sharp, but Don Draper has lost his edge
    Google finds a lift into space will never get off the ground as there is no material strong enough for a cable from Earth into orbit

    Google finds a lift into space will never get off the ground

    Technology giant’s scientists say there is no material strong enough for a cable from Earth into orbit
    Westminster is awash with tales of young men being sexually harassed - but it's far from being just a problem in politics

    Is sexual harassment a fact of gay life?

    Westminster is awash with tales of young men being sexually harassed - but it's far from being just a problem in politics
    Moshi Monster creator Michael Acton Smith: The man behind a British success story

    Moshi Monster creator Michael Acton Smith

    Acton Smith launched a world of virtual creatures who took the real world by storm
    Kim Jong-un's haircut: The Independent heads to Ealing to try out the dictator's do

    Our journalist tries out Kim Jong-un's haircut

    The North Korean embassy in London complained when M&M Hair Academy used Kim Jong-un's image in the window. Curious, Guy Pewsey heads to the hair salon and surrenders to the clippers
    A History of the First World War in 100 moments: A forgotten naval victory in which even Nature played a part

    A History of the First World War in 100 moments

    A forgotten naval victory in which even Nature played a part
    Vespa rides on with launch of Primavera: Iconic Italian scooter still revving up millions of sales

    Vespa rides on with launch of the Primavera

    The Vespa has been a style icon since the 1950s and the release this month of its latest model confirms it has lost little of its lustre
    Record Store Day: Independent music shops can offer a tempting alternative to downloads

    Record Store Day celebrates independent music shops

    This Saturday sees a host of events around the country to champion the sellers of well-grooved wax
    Taunton's policy of putting philosophy at heart of its curriculum is one of secrets of its success

    Education: Secret of Taunton's success

    Taunton School, in Somerset, is one of the country's leading independent schools, says Richard Garner
    10 best smartphones

    10 best smartphones

    With a number of new smartphones on the market, we round up the best around, including some more established models
    Mickey Arthur: Aussie tells ECB to stick with Ashley Giles

    Mickey Arthur: Aussie tells ECB to stick with Ashley Giles

    The former Australia coach on why England must keep to Plan A, about his shock at their collapse Down Under, why he sent players home from India and the agonies of losing his job
    Homelessness: Why is the supported lodgings lifeline under threat?

    Why is the supported lodgings lifeline under threat?

    Zubairi Sentongo swapped poverty in Uganda for homelessness in Britain. But a YMCA scheme connected him with a couple offering warmth and shelter
    A History of the First World War in 100 Moments: When the world’s biggest shed took over Regent’s Park

    A History of the First World War in 100 Moments

    When the world’s biggest shed took over Regent’s Park
    The pain of IVF

    The pain of IVF

    As an Italian woman vows to keep the babies from someone else’s eggs, Julian Baggini ponders how the reality of childbirth is often messier than the natural ideal