Estrogens Found to Modestly Increase Breast Density
Research reports increased density in ethnically diverse women that is sustained over two years
WEDNESDAY, Nov. 11 (HealthDay News) -- In postmenopausal women, the use of conjugated equine estrogens (CEEs) may lead to a small increase in mammographic density maintained over 24-months, according to a study published online Nov. 9 in the Journal of Clinical Oncology.
Anne McTiernan, M.D., of the Fred Hutchinson Cancer Research Center in Seattle, and colleagues compared mammographic density in 435 postmenopausal racially and ethnically diverse women randomly assigned to 0.625 mg of CEE daily or placebo.
After one year, the researchers found a modest but significant increase in mammographic density in women taking CEEs as compared to controls (1.6 percent increase versus a 1 percent decrease). The effect was similar after two years (1.7 percent increase versus a 1.2 percent decrease), and was greatest in women aged 60 to 79 years of age.
"Use of CEE results in a modest but statistically significant increase in mammographic density that is sustained over at least a two-year period," the authors conclude. "The clinical significance of the CEE effect on mammographic density remains to be determined."
Wyeth-Ayerst Research Laboratories provided the active study drug and placebo. Several authors also reported financial relationships with pharmaceutical and medical device companies.