BBC News HEALTH New concerns over mammogram

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BBC News HEALTH New concerns over breast screening

BBC News HEALTH New concerns over breast screening. htm

 

- http://news.bbc.co.uk/hi/english/health/newsid_1607000/1607113.stm -

 

New concerns over breast screening Spotting cancers: But do mammograms save

lives?

 

A fresh row has broken out over controversial claims that screening for

breast cancer may not actually be saving lives. The research was first

published last year, but has been re-examined following a series of protests

from cancer organisations over the findings. Now one of the world's leading

medical journals, The Lancet, agrees that there is not enough evidence from

large-scale trials to support breast screening. However, cancer charities

and the UK cancer screening programme disagree strongly with their verdict.

At present, there is no reliable evidence from large randomised trials to

support screening mammography programmes

 

Richard Horton, Editor, The Lancet All UK women aged between 50 and 64 are

currently offered screening once every three years. It is hoped that tumours

may be spotted earlier, making treatment more likely to provide a cure.

Currently, it is reckoned that as many as 300 lives are saved a year by

breast screening - and more recent estimates suggest this annual figure is

climbing rapidly. However, two Danish researchers from the Nordic Cochrane

Centre in Copenhagen have re-examined the seven large-scale studies looking

into the effectiveness of breast screening. They say that the studies which

support breast screening are either flawed or weak, with the only two high

quality studies showing no benefit at all. In addition, they suggest that

screening may result in women receiving more aggressive treatments for

cancer, increasing the number of mastectomies by approximately 20%. They

write, in The Lancet: " We hope that women, clinicians and policy-makers will

consider these findings carefully when they decide whether or not to attend,

or support screening programmes. " Flood of criticism The Danish pair, Peter

Gøtzsche and Ole Olsen, first voiced these criticisms last year, and

provoked a flood of protest as a result. In the light of this, they say,

they have thoroughly reviewed their work - and reached the same conclusion.

" We found the results confirmed and strengthened our original conclusion, "

they wrote. However, cancer organisations in the UK have repeated their

attacks on the conclusions.

 

We found the results confirmed and strengthened our original conclusion

 

Peter Gøtzsche and Ole Olsen, report authors Many are worried that any

adverse publicity about breast screening will dissuade women from coming

forward. Stephen Duffy, an expert in breast screening from the Imperial

Cancer Research Fund, said that the five studies which supported the use of

mammograms should not have been excluded. He said: " Studies in the UK and

Sweden by ICRF and others have shown breast cancer screening substantially

reduces women's risk of dying of breast cancer. " Research published only in

May demonstrated that women who attend regular breast screenings may reduce

their risk of dying by more than 50%. " Disagreements A spokesman for the UK

Breast Screening Programme agreed: " The way Gøtzsche and Olsen classified

studies was based on criteria that would not be agreed by many experts in

the field.

 

Studies in the UK and Sweden by ICRF and others have shown breast cancer

screening substantially reduces women's risk of dying of breast cancer

 

Stephen Duffy, Imperial Cancer Research Fund " Indeed many researchers would

classify all seven studies as of similar quality, and when the results from

all seven studies are combined, there is clear evidence of the benefit from

mammography. " If existing studies are too weak to support the use of breast

screening, then the chances of organising large-scale replacements are slim,

as these would have to involve a sizeable " control " sample who would not be

screened for the purposes of comparison. As most clinicians already feel

that breast screening offers a significant benefit, it would probably be fel

t ethically unsound to leave so many women without it. However, the fact

that The Lancet now backs the Danish team is a significant move in

supporting those who question the benefits of breast screening. Editor

Richard Horton wrote: " Women should expect doctors to secure the best

evidence about the value of screening mammography. " At present, there is no

reliable evidence from large randomised trials to support screening

mammography programmes. " Professor Michael Baum, from the Portland Hospital

in London, says that it is now right that women should be presented with all

the evidence about screening before they give their consent. He said: " Even

with the most optimistic estimates on saving lives, you would still have to

screen 1,000 women for 10 years to save one life. " If you have one

significant adverse event which costs a life in this group over this period,

all that benefit is cancelled out. " The Lancet is a highly influential

journal and if they are backing this review, it's highly significant. "

WATCH/LISTEN

 

ON THIS STORY

 

The BBC's Karen Allen " The scientists are being backed by one of the most

respected medical journals " Cancer surgeon Professor Michael Baum " The

statistics have to be taken very seriously " On the BBC's Today programme:

Ole Olsa, one of the authors of the report, and Julietta Patnick of the NHS

screening programme