New Test for Breast, Ovarian Cancer?
Inherited DNA-Repair Defect Puts Women at High Risk of Breast, Ovarian Cancer, Shows Study
Sept. 15, 2006 -- Researchers think they have found a new way to identify
women at high risk for breast and ovarian cancer -- by checking for unstable
DNA in their ovary cells.
The researchers concluded such a test could be a useful screen after finding
that women with a strong family history of breast or ovarian cancertend to
inherit a defect that impairs DNA repair.
The genetic defect leads to low levels of a protein that repairs DNA in
ovary cells - and such ovary cells tend to have broken chromosomes.
It's not yet clear exactly why the defect leads to breast and ovarian
cancer, note Oregon Health & Science University researchers Tanja Pejovic,
MD, PhD, and colleagues.
But testing ovary cells for susceptibility to chromosome breakage would tell
women with family histories of these cancers whether they should consider
preventive measures, such as mastectomy or removal of their ovaries.
"Once this method is fully developed, we will be able to tell a young
woman who has a family history of ovarian or breast cancer, but who wants to have children,
whether she is at risk or not, without removing her ovary," Pejovic said in
a news release.
BRCA1 and BRCA2 Not the Whole Story
Current genetic testing can tell a woman whether she carries the BRCA1 or
BRCA2 genes linked to breast and ovarian cancer.
But not all women who inherit breast or ovarian cancer risk carry those
In the newly reported study, Pejovic's team examined ovary cells from three
groups of women who had their ovaries removed.
One group of eight women had ovarian cancer. A second group of six women
came from families at high risk of ovarian cancer, and were having their
ovaries removed as a preventive measure.
The third group had no cancer or family history of cancer, but had other
The researchers found that ovary cells from five of the high-risk women, and
from three of the women with ovarian cancer, were highly susceptible to a
chemical that damages DNA.
And five of these eight women with susceptible ovary cells had low levels of
the DNA-repair protein called FANCD2.
"We have discovered that, by testing ovarian cells for chromosome
breakage, we may be able to identify many more women at risk for ovarian and
breast cancer than by using BRCA1 and BRCA2 mutation testing," Pejovic
said. "We are also suggesting that low levels of FANCD2 protein are
associated with this increased chromosome breakage."
While the women in the study had their ovaries removed, Pejovic says any
future testing would use minimally invasive surgery to scrape just a few cells
from a woman's ovary.
The findings appear in the Sept. 15 issue of the journal Cancer