June 3, 2007: Researchers from the
University of Cambridge have identified four new
genes that significantly affect a woman's risk of
developing breast cancer. These new findings based
on a large study could allow doctors to predict
cancer risk more accurately, and guide treatments
to prevent and cure the disease, according to a
report in Nature.
Breast cancer, which affects about one in every
nine women in Britain and the United States, is
known to have a strong genetic influence. But
until now, known genes could account for only
about a quarter of the genetic component of cancer
risk. To search for some of the many other genes
thought to make small differences to a woman's
breast-cancer risk, the researchers compared the
genomes of some 4,400 women with breast cancer
with those of about 4,300 who did not have the
disease. As more genes are identified, tests will
become more predictive.
Scientists found 30 differences in single DNA
bases that seemed to be linked to the disease.
These were then compared in more than 20,000 women
with breast cancer and in a similar number of
Three of the newly discovered genes are involved
in controlling the growth of cells. The gene with
the strongest association was fibroblast growth
factor receptor 2, or FGFR2. Women who have two
copies of the high-risk version of this gene —
about 16% of the population — have a 60% greater
chance of developing breast cancer than do those
with no copies of the gene.
At present, scanning these newly discovered genes
would tell us little about a woman's cancer risk.
But as more and more genetic risk factors are
uncovered, genetic profiling could give doctors a
fine-grained picture of individual risk, and could
even lead to bespoke treatments offering the best
chance of preventing or treating the disease.
BY OUR PHARMA CORRESPONDENT