[Breast cancer induced by estrogens in a prostate cancer patient]

The authors report a case of malignant breast tumour induced by oestrogens in a patient treated for 7 years for carcinoma of the prostate. They review the literature on the subject and stress the important diagnostic and prognostic role of hormonal receptor assays. These allow the much more numerous cases of mammary metastases of prostatic cancer to be distinguished and, in cases of primary malignant tumour, they permit the choice of the best possible hormone therapy available.