An international panel of pathology experts also conducted a blind review of the 152 samples and confirmed Fiscella's findings, she said. The results suggest that if mifepristone or PRMs with similar properties are eventually approved for treatment of uterine fibroids, pathologists will have a reliable way to track and compare the effects of different doses and treatment schedules (weekly versus daily) on patients during their childbearing years.
The National Institute for Child Health and Human Development funded the study.
Fiscella said larger studies with longer follow-up are needed to more fully characterize the low-dose effect of mifeprisone, and to confirm that changes in the uterus resolve after a woman stops taking the drug.
The Food and Drug Administration approved mifepristone in 2000 for the sole purpose of ending unwanted pregnancies, and has since issued warnings due to a small number of deaths that occurred at the highest doses. Distribution of the drug is strictly controlled, although the FDA does allow it to be studied by qualified physicians. In addition to research into its effect on common gynecological conditions, scientists in California reported in the journal Science in 2006 that mifepristone blocked the formation of breast tumors in mice, suggesting a potential new path to interfere with the hormone progesterone's role in breast cancer. Since then mifepristone has been actively studied by other scientists as a potential cancer treatment.
Leiomyoma, the medical term for uterine fibroids, routinely causes iron-deficiency anemia due to excessive menstrual bleeding. Thousands of women annually opt for hysterectomies, a major surgery, or have the fibroids removed through minimally invasive embolization because no other medical treatment has been proven
|Contact: Leslie Orr|
University of Rochester Medical Center