There may be another use for the abortion pill — aside from stirring up controversy. Researchers from the University of California–Irvine have found that mifepristone, a chemical compound found in the abortion pill, helps thwart the growth of mammary tumors that often lead to breast and ovarian cancers.

The study, which will be published in Science, found that mifepristone prevents tumors by inhibiting progesterone — a female hormone involved in the menstrual cycle and pregnancy. Progesterone has been found to encourage mammary cells to spread in women that carry a breast cancer gene and in some cases, ultimately lead to cancer.

The researchers studied the affects of mifepristone, an anti-progesterone, on mice that had BRCA-1 — a mutated gene that significantly increases the risk of developing breast and ovarian cancers. More than half of women who have BRCA-1 will develop breast or ovarian cancer by age 70. The mice that were treated with mifepristone did not develop tumors by the time they were a year old, but the untreated mice all developed tumors by eight months of age.

What it means: Progesterone encourages tumors to develop when BRCA-1 is present by increasing the speed of cell division. But the researchers have discovered that when mifepristone is administered, it acts as a binding process and blocks progesterone. The discovery could lead to novel ways to prevent breast and ovarian cancer in women that have a genetic predisposition.

From the Archive:

Feb.18, 2002: Rethinking Breast Cancer
May. 28, 2001: New Hope for Cancer