Daughters born to women who had excess levels of oestrogen during pregnancy
may be at increased risk for breast cancer, a new study suggests.
That's because high oestrogen levels in the womb can disable the powerful
breast cancer tumour suppressor gene BRCA1 in daughters, the researchers at
Georgetown Lombardi Comprehensive Cancer Center said in a Georgetown news
What the study found
Their study of one-year-old girls whose mothers had high oestrogen levels
during pregnancy also found that the daughters had other gene abnormalities that
can contribute to the risk of breast cancer and breast cancer recurrence.
This includes a gene defect in the so-called unfolded protein response
pathway, which has been linked to breast cancer risk and resistance to the
breast cancer drug tamoxifen.
Although the study found an association between high oestrogen levels in
pregnancy and factors that raise breast cancer risk in daughters, it did not
prove cause and effect.
If the findings are confirmed, they could be used to identify women at
increased risk for breast cancer and to lower their risk before the disease
develops, the researchers said.
There are drugs available that may make it "possible to reverse the increase
in breast cancer risk and prevent development of resistance to tamoxifen in
these women," study lead author Leena Hilakivi-Clarke, a professor of oncology
at Georgetown Lombardi, said in the news release.
The study was to be presented at the American Association for Cancer
Research annual meeting, in Washington, DC. The data and conclusions of research
presented at meetings are typically considered preliminary until published in a
peer-reviewed medical journal.
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