Compound in Abortion Pill May Prevent Breast and Ovarian Cancer

The chemical compound in the "abortion pill" has beenpercent of women with the mutated BRCA-1 gene
found to prevent the development of mammarydevelop these cancers.
tumors caused by the mutant gene responsible forThe researchers studied mice that possessed the
the majority of breast and ovarian cancers, a groupmutated BRCA-1 gene. Mice treated with
of scientists from UC Irvine reported.mifepristone, an anti-progesterone compound, did not
The key compound, known as mifepristone,develop mammary tumors after 12 months. All of the
prevented breast tumors by inhibiting the productionuntreated mice developed tumors by eight months
of progesterone. progesterone is a hormone involvedof age.
in the female reproductive cycle which is found in theProgesterone, secreted by the ovaries, is essential to
tissues of the breast. The discovery may open upthe term of a pregnancy. Mifepristone, also called
more, and far more palatable options for womenRU486, is designed to abort pregnancy in the first
who have a genetic predisposition to developingtrimester by shutting down the secretion of
breast and ovarian cancers. Currently, the typicalprogesterone and ending the viability of the fetus. In
prevention method relies on the surgical removal ofsmaller doses, it is also an emergency contraceptive.
breasts or ovaries for the majority of these women.UCI researchers found that progesterone encourages
The study is published in the December 1 issue ofthe development of cancer when the mutated
Science.BRCA-1 is exists because it increases the rate of cell
"We found that progesterone plays a role in thedivision. Mifepristone, they discovered, blocked a
development of breast cancer by encouraging thebinding process that is necessary for progesterone to
proliferation of mammary cells that carry a breastcause the cells to divide.
cancer gene," said Eva Lee, the study's lead authorPrevious studies have linked high levels of
and a professor of developmental and cell biologyprogesterone with an increased risk of breast cancer.
and biological chemistry at UCI. "Mifepristone canThis was proven to be especially true for menopausal
block that response. We're excited about thiswomen who received hormone-replacement therapy
discovery and hope it leads to new options forthat included progesterone and estrogen to ease
women with a high risk for developing breast cancer."things like hot flashes and night sweats. The previous
In the study, Lee and her colleagues addressed howfindings, combined with this new data, lead scientists
mifepristone affects the functionality of mutatedto believe that anti-progesterone could provide
genes called BRCA-1 genes. This group of mutatedwomen at risk with more prevention options in the
genes is widely studied by cancer researchersfuture.
because a mutated version of this gene significantlyThe research was conducted with the backing of the
contributes to the development of breast andNational Cancer Institute, the Breast Cancer Research
ovarian cancers. By the age of 70, more than 50Foundation and the Department of Defense.