[Estrogens and endometrial cancer].

Research dealing with the association between estrogens and endometrial cancer is discussed in this editorial. Three major areas of research are considered: 1) the relationship between endogenous estrogens and endometrial cancer; 2) endometrial cancers produced in experimental animal studies; and 3) the relationship between exogenous estrogens and endometrial cancer in humans. The possibility that endometrial cancer is the final stage of a disruption in endocrine homeostasis is also considered; it is known that continuous, uninterrupted stimulation of estrogen activity causes endometrial hyperplasia, and it is possible that in some cases this may progress to a malignant process. The author concludes that the use of exogenous estrogen preparations presents an increased risk of endometrial cancer only when they have been used for a long duration, such as 5 or 10 years on a continuous basis. He suggests that if a woman accepts the possible risk of developing endometrial hyperplasia, the gynecologist must accept responsibility for prescribing the smallest dose of estrogen which is appropriate, and for stopping estrogen therapy as soon as any hyperplastic changes are observed in the endometrium.