Hormone therapy is used to change the way hormones stimulate cancer
growth. These medicines either block the effects hormones have on the cancer
cells or block the production of the hormones.
If tests show that the breast cancer cells have estrogen and
progesterone receptors (ER/PR-positive), hormone therapy may be used. Tamoxifen
and aromatase inhibitors are the most commonly used hormonal therapies. Other
hormonal therapies include progestins, such as megestrol (Megace), and
antiestrogen, such as fulvestrant.