Women who are given estrogen without progesterone have uteri that are stimulated all the time, which can lead to uncontrolled growth which is cancer. However, gynecologists do not yet have the data to say the same thing for breast cancer. A recent article in the Journal of the American Medical Association recommends that clinical trials be started to find out if postmenopausal estrogen replacement can be given to women who already have breast cancer. The authors show that there is no good evidence that estrogen replacement therapy spreads breast cancer. The original data showing that postmenopausal estrogen may cause breast cancer were done in Europe on women who were given a very potent type of estrogen that has not been available in the United States.
Extensive trials are underway now to see if the same applies to humans.
I'm Dr. Gabe Mirkin on Fitness. Estrogen after the menopause helps prevent osteoporosis, heart attacks, strokes, hot flushes, depression, loss of memory, vaginal dryness and a decrease in height. FW Lafferty, ME Fiske. The benefits and risks of hormone replacement therapy. HA Risch, GR Howe.