Long-term consequences of estrogen and estrogen-progestin replacement

Except for the control of smoking, hormone replacement therapy (HRT) is potentially one of the most useful means of preventing major causes of morbidity and mortality in older women, who are likely to spend more than one-third of their lives in a postmenopausal (estrogen-deficient) stage. A full assessment of the overall long-term effects of noncontraceptive estrogens--with and without cyclically added progestins--therefore is needed urgently. This paper briefly reviews the available epidemiologic findings to date, with emphasis on a prospective study in Uppsala, Sweden. An increase in the risk of endometrial cancer which is substantially dependent on dose and duration of the exposure has been established, whereas a biologically plausible protective effect of progestins has been documented in only a few studies. A moderate, perhaps twofold, increase in the incidence of breast cancer has been found in several recent studies, notably among long-term and/or current users of potent estrogens; there is no evidence that progestins counteract this adverse effect. The risk of osteoporotic hip fractures can be reduced substantially, at least during ongoing, treatment starting early after menopause. A 25 to 50 percent reduction in cardio...Continue Reading