New studies, appearing in the Journal of Steroid Biochemistry and Molecular Biology and Breast Cancer Research, detail interesting findings on a new drug developed by University of California Davis (UCD) and Finnish researchers. The tamoxifen-like drug developed as a treatment for vaginal atrophy, may also help to prevent breast cancer, the studies suggest.
The drug - ospemifene - is about to enter Phase 3 clinical testing in the U.S. for the treatment of vaginal atrophy, a common condition among postmenopausal women. "These reports indicate that prevention of breast cancer may be another benefit of the use of ospemifine," said Michael W. DeGregorio, from UC Davis. "The findings are very encouraging."
Vaginal atrophy can occur when decreased estrogen levels lead to a thinner, less elastic and more fragile vaginal lining. The problem affects 10 to 40 percent of post-menopausal women. Symptoms may include dryness, itching, burning, irritation, a feeling of pressure and pain or light bleeding with sex. Estrogen creams, rings, patches or oral supplements are often prescribed to treat vaginal atrophy.
DeGregorio explained that ospemifene is one of a class of drugs called selective estrogen receptor modulators. In tests so far, ospemifene appears to have a unique estrogen-like effect on the vagina, yet a neutral effect on the endometrium, or lining of the uterus, and no aggravation or initiation of hot flashes. "[Co-researcher] Dr. Lammintausta and I worked for many years to find a drug that would have beneficial effects in healthy, postmenopausal women but be absolutely safe," said DeGregorio. "We're gratified that this seems to be the case."
The tamoxifen-like effects were discovered when DeGregorio compared the ability of ospemifene and tamoxifen to inhibit breast cancer in mice exposed to a carcinogen. It was found that ospemifene and tamoxifen both inhibited breast cancer development and that mice in the ospemifene group were 95 percent less likely to develop breast cancer.
In the second study, led by Jeffrey P. Gregg, it was found that both tamoxifen and ospemifene inhibited the growth and progression of pre-malignant breast lesions. Both drugs decreased the growth of the lesions by reducing the proliferation rate of the precancerous cells.
Source: University of California, Davis - Health System