We do know that some types of breast cancer are stimulated to grow in the presence of estrogen. For this reason, women with estrogen positive breast cancer cannot take hormone replacement. Several studies have looked at whether women taking hormone replacement are more likely to develop breast cancer. Some have found no difference in incidence of breast cancer, regardless of whether hormone replacement was used. Other studies have found a slightly increased incidence of breast cancer in women who take estrogen, especially in those who have taken it for many years.
More study is needed, in order to know for sure.
A woman s risk of breast cancer already increases as she gets older. If taking hormone replacement therapy increases this risk at all, it appears to be by a very small amount. Researchers have found that women who have a family history of breast cancer do not seem to increase their risk of breast cancer by taking hormone replacement therapy. There are many health benefits to taking hormone replacement therapy. When deciding whether to take hormone replacement, a woman should consider her own health conditions, along with her personal goals and beliefs.