[Medical adverse effects of chemoprevention: the example of tamoxifen].

: Tamoxifen, a synthetic antiestrogen widely used for the treatment of breast cancer, is also being proposed for the prevention of this cancer among women at high risk for the disease. Such an approach requires an objective and accurate evaluation, not only of the expected beneficial effects, but also of the potential iatrogenic side effects which could result from the administration of this drug to a population of healthy women. The present article summarizes our present knowledge which results from studies, all carried out on women with breast cancer: we review the side effects on the female genital apparatus, the ovarian and non ovarian endocrine side effects, the effects on cardio-vascular and thromboembolic risks, on bone metabolism and on ocular and hepatic side effects. The potential carcinogenic role is only briefly mentioned since it has already been the subject of a publication in this journal.