A genetic mutation implicated in an increased risk of breast andovarian cancers also significantly increases the risk of pancreatic andprostate cancers in men, finds research in the Journal of Medical Genetics.
The mutation in the BRAC2 gene may also increase the risk of bone and throat cancers, the data suggest.
The Dutch researchers investigated 139 families with 66different mutations of the BRAC2 gene between them. The families wereall drawn from a national register of families with breast and ovariancancers in several family members.
To provide a more accurate picture of risk, the researchersavoided the known carriers, and studied the incidence of cancers amongfamily members with a 50% chance of being a carrier, amounting to 1811people.
They then calculated the overall risk of developing thesecancers in comparison with the expected rates in the generalpopulation.
Among the 441 people who were tested for BRAC2, just over two thirds (69%) carried the mutation.
In total, there were 158 cases of cancer among the 303 carriersof the genetic mutation compared with just 18 cases among the 138 whodid not carry the mutation.
There were higher numbers of prostate, pancreatic, pharyngeal and bone cancers than would be expected in the general population.
Compared with the general population carriers of the BRAC2genetic mutation were almost seven times and eight times as likely tohave, respectively, pharyngeal and pancreatic cancers. Male carrierswere more than twice as likely to have prostate cancer.
Carriers were also around 15 times as likely to have bonecancer, although the authors point out that this could have been theresult of spread from another primary cancer.
Almost all of these increased risks were significant for men only, and tended to be stronger for people under the age of 65.
As 11 of the 24 men with prostate cancer had died, the authorssuggest that early radical treatment for the disease might be offeredto men who carry the genetic mutation, rather than the watchfulwaiting, which is common policy.
[Cancer risks in BRCA2 families: estimates for sites other than breast and ovary J Med Genet 2005; 42: 711-19]
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