PHARMACOLOGIC studies in animals (1, 2, 3) indicate that TACE1 behaves in some respects like other estrogens but also possesses a number of unique properties. Specifically, it is absorbed following oral administration and then accumulates in the body fat, from which it is liberated gradually in ever decreasing quantities for a substantial period of time (3). In animals, the pituitary enlargement, which is a characteristic result of the repeated administration of other estrogens, does not occur (3). Similarly, effects upon the adrenal and ovary mediated through the pituitary are much less pronounced than with other estrogens (3). Clinical use of this latter phenomenon has been reported (4) in the palliative treatment of prostatic carcinoma. The administration of TACE does not appear to be complicated by the formation of adrenal androgens, as may happen during the usual hormone therapy of this condition. Because of the prolonged and gradually decreasing estrogenic stimulation following a single course of TA...