Effects on the breast of drugs used in fertility regulation.

The action of fertility-regulating drugs on the breast is discussed. Compounds such as steroids act directly on breast tissues, whereas others, such as clomiphene or gonadotrophin, act indirectly. There can be differential responses of the alveolar and ductal systems. Tissues of a breast tumour typical of epithelial tissues were analysed for changes in cytosolic and nuclear receptors for oestradiol-17 beta and progesterone following its exposure to these steroids. Effects on cell multiplication and receptor density were identified. The relationship of these findings to benign breast disease and oral contraceptives is discussed.