Cancer Research UK urges caution over BRCA gene/X-ray link
Initial results of a Europe-wide study of women carrying the BRCA breast cancer predisposition genes have suggested that exposure to X-rays may increase their risk of the disease.
Although faults in these genes are rare in the population as a whole, women who inherit them from either parent have around an 80 percent likelihood of developing breast cancer at some point in their lives.
Cancer Research UK has voiced caution on the research however, pointing out that the finding has yet to be corroborated by further or more extensive testing.
Professor John Toy, the charity?s medical director said "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.
"A very small percentage of the population carries a BRCA1 or BRCA2 mutation.
"This study looked at chest x-rays and not mammograms. A paper in the Lancet Oncology earlier this year found that the type of mammograms used for screening did not increase the risk of breast cancer in women with these mutations"
The study was compiled from questionnaires filled in by 1,600 women involved in the BRCA1/2 Carrier Cohort Study (IBCCS), a Europe-wide research project.
Women who carried one of the BRCA genes who said they had previously had a chest X-ray were found to be 54 per cent more likely to develop breast cancer than carriers who hadn't, the research suggested.
BRCA carriers who reported having had an X-ray before the age of 20 were estimated to be 2.5 times more likely to develop breast cancer by age 40, compared to women who hadn't.
The scientists noted that the study was limited by not having any record of the doses of X-rays received, and the fact that women who had had cancer may have more extensive recall of details of their medical history, such as experience of being X-rayed.
Lead researcher Dr David Goldgar said that if the findings are confirmed in future studies women with a family history of BRCA1/2-related breast cancer may wish to consider alternative scans.
The research has been published in the 26th June edition of the Journal of Clinical Oncology.
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