Experiments in mice show that treating uterine fibroids with gene therapy that inactivates the fibroid’s estrogen receptors causes them to shrink. This might lead to a way to deal with fibroids without impairing a woman’s fertility, researchers say.

Uterine fibroids are non-malignant tumors that can cause severe pain and bleeding. They’re seen “more and more in women who either haven’t completed their family or have not even had their first pregnancy,” Dr. Ayman Al-Hendy of the University of Texas Medical Branch in Galveston told AMN Health.

The problem is that “most current treatments - hysterectomy or uterine artery embolization - end the fertility potential of those women.”

To investigate a different approach, Al-Hendy and colleagues first grew fibroids under the skin of lab mice for approximately 2 to 3 weeks. The team then injected the growths directly with an engineered virus that conveyed a mutated estrogen receptor gene into the fibroid cells.

Beginning as early as 1 week after treatment, tumors in the animals were significantly smaller than those in comparison “control” groups, according to a report in the American Journal of Obstetrics and Gynecology.

Experiments in which fibroid cells were grown in a lab dish showed that treatment with the gene therapy arrested cell proliferation and induced cell death.

The researchers note that fibroids are an attractive target for gene therapy because the condition is localized and it’s easy to inject the growths directly. Moreover, clinical improvement does not require complete eradication of fibroids, as even a modest decrease in size decreases symptoms.

The treatment “should not interfere with the fertility potential of the patient,” Al-Hendy concluded. “Patients who still want to become pregnant represent a group who we have failed so far, and we hope with this approach that we’ll have an option for them for the future.”

SOURCE: American Journal of Obstetrics and Gynecology, November 2004.