ABSTRACT
Cancers of the breast, corpus uteri, and ovary account for more than a quarter of all cancer deaths among women (2). In the United States from the mid 1960s until 1975, rates of endometrial cancer showed an unprecedented climb; replacement estrogen use during this time also rose sharply (3). The suspicion that estrogen stimulation may contribute to the development of endometrial cancer goes back at least to 1946 (4), while the role of estrogens in the genesis of breast cancer was first suggested as long ago as 1836 (5). In 1975, two articles were published which showed large relative risks of fivefold to seven-fold for endometrial cancer among ever-users of estrogen compared to never-users (6, 7). The effect of these publications was to reduce dispensed prescriptions of noncontraceptive estrogens by 50% between 1975 and 1980; concurrently, the incidence of endometrial cancer fell as well. (3).
