A synthetic steroid compound used to abort pregnancy could fight breast and ovarian cancer, caused by a mutant gene, from growing, according to researchers at the UniversityCalifornia, Irvine.
The research published in the December 1 issue of journal Science, revealed that by blocking the hormone progesterone in breast tissue cells, the drug can also prevent formation of tumors.
Cancer researcher Eva Lee and other scientists discovered that mice treated with mifepristone, an anti-progesterone compound, did not develop breast tumors by the time they reached one year of age, while all of 25 untreated mice developed tumors by 8.7 months of age. There was also a third group of mice who were treated with a placebo pellet, developed tumors by the age of 5.2 months, the study said.
Currently, the best way for women with a BRCA1 mutation to substantially reduce their risk is to surgically remove their breasts and ovaries before tumors have a chance to form.
Lee said RU-486 probably wouldn’t be the best candidate for a human treatment because in addition to blocking progesterone, it binds with receptors involved in immunity and other important functions.
For short-term use to end a pregnancy, that isn’t likely to be a problem. But if patients are going to take a drug for years, it should target progesterone more precisely, she said.
The study was funded by the National Cancer Institute, the Department of Defense and the Breast Cancer Research Fund, a private foundation based in New York.
