Controversies Surrounding Estrogen Use in Postmenopausal Women

Abstract

OBJECTIVE: To provide an overview of controversies regarding the use of estrogen in postmenopausal women. DATA SOURCES: A MEDLINE search was conducted to identify pertinent literature published since 1990. Recently published textbooks devoted to the subjects of menopause and women's health were also reviewed, particularly their bibliographies. The bibliographies of selected review articles were also reviewed. STUDY SELECTION: Due to the vast amount of literature, only the most relevant published studies were reviewed. Review articles and book chapters authored by researchers of international reputation were also reviewed. DATA EXTRACTION: Identified studies from the primary literature and selected reviews were carefully reviewed. Information regarding the use of estrogen in postmenopausal women was extracted. Particular attention was given to areas of controversy commonly dealt with in the lay media. DATA SYNTHESIS: The number of postmenopausal women in the US will approach 60 million in the next decade. Despite numerous potential benefits, many women elect to not take estrogen due to fear of cancer or poor understanding of the long-term consequences of menopause and the beneficial effects of estrogen replacement therapy. Many women rely on the news media for information about hormone therapy and subsequently become confused regarding the benefits and risks. Estrogen relieves climacteric symptoms such as hot flushes and symptoms related to genitourinary tissue atrophy. Outcomes from controlled clinical trials are lacking, but numerous epidemiologic studies document clinically significant decreases in cardiovascular disease and osteoporotic morbidity and mortality. Unopposed estrogen increases the risk for endometrial cancer, but addition of a progestin for at least 10 days per cycle effectively reduces this risk to that of women who do not take estrogen. The association between postmenopausal estrogen use and breast cancer remains controversial, despite the results of numerous observational studies. This uncertainty regarding estrogen replacement and breast cancer risk can actually be reassuring when placed in proper perspective.