The subject matter of the instant invention is pertinent to the field of cancer treatment. In particular, the instant invention is relevant to the treatment and or prevention of breast cancer in a patient. Compositions for practicing the methods, comprising selective progesterone receptor modulators, which function as progesterone agonists in the uterus and as progesterone antagonists in the breast tissue and exhibit only low affinity for glucocorticoid and estrogen receptors, are also disclosed. Embodiments of the instant invention also disclose methods for preventing the development of breast cancer in patients undergoing hormone replacement therapy or estrogen therapy.