The estrogen--cancer controversy.

Postmenopausal women should not be denied estrogen therapy because of the controversy about the alleged causal relationship of estrogens to endometrial cancer. A prestigious team of biostatisticians reviewed three publications that claimed this relationship and concluded that no such association could be confirmed. Although the incidence of endometrial cancer has doubled in the past 25 years, there is no valid basis for the assumption that the widespread use of estrogens is the cause. The incidence also has increased in Norway and Czechoslovakia where estrogens are rarely used. Moreover, the histologic pattern of endometrial dysplasias is such that many pathologists will make a diagnosis of endometrial cancer as a safeguard for the patient. Thus the statistics for the incidence of endometrial cancer may be inflated. As a test, the administration of 200 mg of an oral progestogen over 5-10 days will convert a histologic pattern of pseudomalignancy, but not of adenocarcinoma, into one of secretory endometrium. Unopposed endogenous or exogenous estrogens may induce hyperplasia, atypical adenomatous hyperplasia or adenocarcinoma in women who are genetically predisposed. To minimize such a possibility, it is advisable to give a 5-7 day course of an oral progestogen so that the endometrium will be shed as monthly intevals. The benefits of hormone replacement therapy for the postmenopausal woman far outweigh the putative risk of endometrial cancer.