[Metrorrhagia and tamoxifen. Apropos of 22 patients treated for cancer of the breast].

The authors report 22 cases of metrorrhagia occurring in the course of adjuvant hormonal therapy for breast cancer using tamoxifen. The anti-oestrogenic effect of this drug is associated with a variable agonistic effect that has been observed in organs with steroid receptors, and especially in the uterus. In this series, the cause of the abnormal bleeding is explained in 17 out of the 22 cases (ie, 3 out of 4) as a paradoxical oestrogen-like effect on the mucosa of the uterus. Two cancers of the endometrium were diagnosed.