Postmenopausal hormone therapy and breast cancer.

ABSTRACT

Given the magnitude of the older female population, the possibility that postmenopausal hormone therapy is associated with an increased risk of breast cancer is an issue of great public and individual importance. Epidemiologic evidence indicates the possibility of a slightly increased risk of breast cancer associated with long durations of postmenopausal estrogen use. However, in a review of the literature, it is apparent that the epidemiologic data are contradictory and do not yield uniform and consistent results. It is further apparent that adding a progestin to a postmenopausal hormone program does not alter the findings compared with the use of estrogen alone. Reasons for this disagreement and lack of definitive evidence are detailed, and it is suggested that any impact of postmenopausal hormone therapy on the risk of breast cancer is unlikely to be great. Finally, the question of whether a woman who has had breast cancer should use postmenopausal hormones is addressed.