[Estrogen therapy and carcinoma of the endometrium (author's transl)]

Abstract

The public discussion and the discussion among gynaecologists about the possible increased risk to develop carcinoma of the endometrium following post menopausal treatment with estrogens has lead to insecurity and restricted attitudes in the prescriptions of estrogens. In a statistic comparison of matched pairs of 130 cases of carcinoma of the endometrium with an equal number of selected control cases the following findings were elucidated: 1. Any estrogen preparations do not increase the relative risk for the development of carcinoma of the endometrium. 2. Differentiation into conjugated estrogens, estriol, oral contraceptives and various other estrogen compounds showed a similar trend. 3. Estrogen-androgen compounds and estrodiol compounds did not increase the relative risk for endometrial carcinoma. 4. The relative risk does not increase by prolonged ingestion of estrogen preparations in general and not for conjugated estrogens especially. 5. In the presence of other risk factors such as nulligravity, hypertension, obesity the relative risk for the development of carcinoma of the endometrium is significantly decreased when estrogens were taken, especially when the coincidental risk factor to estrogen ingestion was obesity. The above results suggest that the restraint in the prescription of estrogen for fear of endometrial carcinoma is not justified.

PIP: A matched pairs analysis of 130 cases of endometrial cancer was undertaken to determine the relationship between post-menopausal estrogen treatment and endometrial cancer. 90% of the cases were in FIGO stage I, 6.9% stage II, and 2.3% stage III. The matching took place according to a wide range of criteria, e.g. age at menopause, age at diagnosis, no. of births, weight, etc., within certain tolerances. After the matching was finished, the information on estrogen use was collated, and the relative risk (RR) for various estrogen preparations was calculated according to the length of estrogen treatment. The number of estrogen users was smaller among the women with endometrial cancer than among the control group (p .01); the RR of endometrial cancer does not increase with estrogen use (RR=.44). The same held true when conjugated estrogens, estriol, estradiol, estrogen-androgen preparations, and ovulation inhibitors were considered separately (.05 p . 05). The RR of endometrial cancer does not increase with the length of estrogen treatment. It was also observed that the RR of endometrial cancer was significantly lower (p .01-.001) among women with predisposing factors such as hypertension, obesity, and nulligravidity. This suggests that the risk of endometrial cancer is not increased by estrogen treatment.