[ RadSafe ] X-rays linked to breast cancer risk

[Dawson, Fred Mr]

Scotsman reports X-rays linked to breast cancer risk

http://news.scotsman.com/index.cfm?id=936332006

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* A chest X-ray could increase the risk of getting breast cancer 
* More than 1 in 500 with the susceptible gene face a dramatic rise in
threat 
* Women with the BRCA1 and 2 mutation should opt for MRI scans 

Key quote "We must interpret these results with caution. This type of
study has inherent limitations because it relies on participants
recalling the X-rays they have received" - Professor John Toy
Story in full TENS of thousands of women have a dramatically increased
risk of breast cancer if they have a chest X-ray, according to research.


A study found that women genetically susceptible to breast cancer were
54 per cent more likely to get the disease if they had been given a
chest X-ray. If they were younger than 20 when X-rayed, the risk of
contracting the disease before the age of 40 increased two and a half
times. 
The researchers said their results raised questions over the use of
mammograms in diagnosing women from families known to have the BRCA 1
and 2 genetic mutations. They said MRI scans - which do not use X-rays -
might be a better option. 
The BRCA 1 and 2 genes make proteins involved in repairing damage to DNA
in breast cells. Mutations to these genes, which affect more than one in
500, leave women with a 40 to 80 per cent chance of developing breast
cancer at some point in their lives. 
According to the findings, a chest X-ray would see the likelihood of
some of these women contracting the disease increase from a "high"
chance to "extremely high". 
Some experts said that, if confirmed, the study could have "significant
practice implications" and "could potentially eliminate" mammographic
screening of young women. However, cancer charities warned against
spreading alarm among women about having mammograms, saying the study
was not "conclusive" as it had been based on people's memories of having
had X-rays in the past. 
Dr David Goldgar, who led the research at the Genetic Epidemiology Group
at the International Agency for Research on Cancer in Lyons, France,
said his study was one of the first to demonstrate "that women
genetically predisposed to breast cancer may be more susceptible to
low-dose ionising radiation than other women". 
However, he stressed the need for further study to confirm the work, as
it was based on people's recollections of having X-rays. 
More than 1,600 women completed questionnaires asking if they had ever
had chest X-rays. The researchers excluded mammograms, saying this would
prejudice a study based on recollections "because of its obvious
relationship to diagnosis". But they said the results "raise the issue
of the potential risks of mammographic screening", which uses X-rays. 
The research appeared in yesterday's edition of the Journal of Clinical
Oncology, and in an accompanying article, Dr Angela Bradbury and
Professor Olufunmilayo Olopade wrote: "If confirmed, this study could
have significant practice implications for the BRCA mutation carriers
and could potentially eliminate mammographic screening as a surveillance
method for early detection of breast cancer in young women." 
Professor John Toy, the medical director of Cancer Research UK, urged
women not to panic. He pointed to a Lancet Oncology study, published
earlier this year, which found no association between mammograms and
breast cancer among those with the BRCA mutations. 
On balance, he said, it was worthwhile to have the screening to allow
early detection of cancer - and therefore more effective treatment -
despite the risk the mammogram could kick-start the disease. "We must
interpret these results with caution. This type of study has inherent
limitations because it relies on participants recalling the X-rays they
have received ... [and it] looked at chest X-rays and not mammograms,"
he said. 
However, Prof Toy said that if the study was found to be correct, it
could lead to more use of MRI scans. He gave as an example an
18-year-old woman with BRCA mutations attending hospital with a broken
rib. "The doctor might say, 'I think you've cracked your rib. Normally,
we'd perhaps take an X-ray and confirm this, but I don't think you have
punctured your lung and you've told me you are a BRCA mutation carrier,
so perhaps we'll agree that we will forgo the X-ray'," he said. 
Dr Sarah Rawlings, of the charity Breakthrough Breast Cancer, said:
"This study does not yet offer conclusive evidence. It's still important
for women to attend their breast screening appointments as mammography
can detect breast cancer early, when it is more likely to be
successfully treated."


Fred Dawson

Fwp_dawson at hotmail.com