A new study suggests that the use of combination hormone therapy is associated with a modest increase in breast density, which is a known risk factor for breast cancer. The findings appear in the Jan. 1 issue of the Journal of the National Cancer Institute. The degree of breast-cancer risk that is associated with breast density is greater than that associated with almost all other known breast-cancer risk factors. A previous analysis of data from the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial, a randomized trial looking at the effects of postmenopausal hormone therapy (estrogen alone or estrogen plus three different progestin regimens) on breast density, showed that some women who used combination estrogen/progestin therapy experienced an increase in breast density. However, the analysis did not look at the magnitude of that increase.
Researchers confirmed that a daily, combined dose of estrogen and progestin increases breast cancer risk in post menopausal women, but added that this risk begins to return to normal about six months after women stop taking the hormones. “It is reassuring that breast cancer risk begins to return to normal six months after women stop combined dose estrogen-progestin therapy,” said Duane Alexander, M.D., Director of the NICHD. “Women, in consultation with their physicians, need to make the most informed decision possible. The study authors have provided them with one more piece of important information.”
Another menopausal myth is challenged: Women with existing coronary disease do not realize improvement in their cognitive function as a result of taking the most common form of hormone replacement therapy, a UCSF study has found. Investigators followed more than 1000 women from ten US test sites for four years. Half took a placebo; the other half took hormone replacement therapy (HRT). Although other, smaller studies have shown an improvement, in the UCSF study the women who received HRT performed no better on standard tests of cognitive function than those who received placebo.