What are the effects of postmenopausal hormone use on the uterus?
Studies have shown that prolonged exposure of the uterus to estrogen without progesterone increases a women’s risk of endometrial cancer (cancer of the uterine lining). By adding progestin to the estrogen regimen, the risk of endometrial cancer can be reduced to nearly the same level as women not using estrogen (104). However, some studies have shown increases in endometrial cancer risk with the combined regimens if progestins are used for less than ten days per month (94, 84). Generally, standard postmenopausal hormones for women who have undergone hysterectomy (surgical removal of uterus) has been estrogen alone, whereas women who have not undergone this procedure have been given the estrogen-progestin combination.
