Mutation in the BRAC2 breast cancer gene may also increase the risk of bone and throat cancers

Sep 1 2005

A genetic mutation implicated in an increased risk of breast and ovarian cancers also significantly increases the risk of pancreatic and prostate 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 66 different mutations of the BRAC2 gene between them. The families were all drawn from a national register of families with breast and ovarian cancers in several family members.

To provide a more accurate picture of risk, the researchers avoided the known carriers, and studied the incidence of cancers among family members with a 50% chance of being a carrier, amounting to 1811 people.

They then calculated the overall risk of developing these cancers in comparison with the expected rates in the general population.

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 carriers of the genetic mutation compared with just 18 cases among the 138 who did 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 BRAC2 genetic mutation were almost seven times and eight times as likely to have, respectively, pharyngeal and pancreatic cancers. Male carriers were more than twice as likely to have prostate cancer.

Carriers were also around 15 times as likely to have bone cancer, although the authors point out that this could have been the result 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 authors suggest that early radical treatment for the disease might be offered to men who carry the genetic mutation, rather than the watchful waiting, which is common policy.

http://jmg.bmjjournals.com/