The risk of endometrial carcinoma from oestrogen therapy of the menopause.

Although there is no doubt that increasing numbers of women are presenting with carcinoma of the endometrium, this could be due only to the fact that many more women live to an age when they are liable to get this cancer. Even when age specific incidence rates are considered, the apparent increase could be due to risk factors other than oestrogens. Recent developments in hormone replacement therapy have placed increasing emphasis on the natural oestrogens, oestradiol and oestrone, but they present problems of their own. Nor has the induction of periodic bleeding by cyclical administration of oestrogens, with or without a progestogen, proved an unqualified success. A special case might yet be made for the weaker physiological oestrogen, oestriol.