Abortion Compound Shrinks Fibroids

ROCHESTER, N.Y., Dec. 7 -- Low doses of Mifeprex (mifepristone) -- the compound at the heart of the abortion pill -- shrink uterine fibroids and improve quality of life for women with the condition, according to researchers here.

In a randomized, placebo-controlled, double-blind trial, women getting Mifeprex also had less bleeding and lower rates of anemia, Kevin Fiscella, M.D., of the University of Rochester, and colleagues, reported in the December issue of Obstetrics & Gynecology.

Improvements were so dramatic that 19 of the 20 women remaining in the treatment group at the end of the study correctly guessed that they had been receiving Mifeprex, compared with nine of 17 in the placebo group who correctly guessed they were not receiving the drug, said Dr. Fiscella and colleagues.

The six-month study, involving 42 women with at least moderate fibroid symptoms and a uterine volume of greater than 160 mL, used doses of 5 mg/day. By comparison, the dose of Mifeprex used to terminate a pregnancy is 600 mg at one time, followed two days later by 400 mcg of Cytotec (misoprostol).

The women were evaluated using the standard Uterine Fibroid Symptoms Quality of Life Questionnaire and Medical Outcomes Study 36-Item Short Form survey. The size of the uterus and fibroid were assessed using ultrasound at baseline, one month, three months, and six months of treatment. Bleeding and pain were assessed monthly, while endometrial pathology was assessed at baseline and six months.

The study found:

• Women getting Mifeprex had an average increase in their quality of life score of 50.1 of a possible 100 points, or a 135% improvement.
• Women in the placebo group had an average increase of 16.7 points, for a 41% improvement.
• The difference among groups was significant at P<0.001.
• Symptom severity decreased significantly in both groups, but within each group, the decline in severity was greater for those getting the drug (from 67 to 21 points) than for those on placebo (from 67 to 50 points).
• Uterine volume decreased an average of 200 mL among women getting Mifeprex, which was significant at P=0.02 and increased an average of 73 mL in the placebo group, which was not significant.
• When the groups were compared the effect of treatment on uterine volume was highly significant at P<0.001.

Bleeding decreased notably in the Mifeprex group: By the end of the study, nine of 22 women in the treatment group had become amenorrheic (including two who were randomized to the treatment arm but withdrew before the study began), compared with none in the placebo group, the researchers reported.

A related measure was anemia -- defined as hemoglobin levels below 12.0 g/dL -- which was not significantly different between the groups at baseline. By the end of the study, the researchers reported only two of 22 women in the treatment group were still anemic, compared with 12 of 20 women in the control group. The difference was significant at P<0.001.

There were no differences in side effects between the groups.

Because there's no medical treatment for fibroids, which affects about half of all women ages 35 to 49, surgery is the usual alternative, From 1998 and 2002, there were more than one million hysterectomies in the U.S. and 150,000 myomectomies as a result of fibroids, the researchers said.

"With no approved treatment for symptomatic fibroids, this study and its findings are very significant," Dr. Fiscella said.

Although the study showed a clear benefit, the researchers said, it was too small to evaluate such issues as pain. A larger trial, they said, is needed to replicate the findings, evaluate other aspects of the treatment effect, including their longevity, and establish the safety of the approach over a longer term.

The researchers reported no conflicts. The study was supported by funding from the National Institute for Child Health and Human Development.