Hormone therapy helps control the growth of cells in the body. Hormones such as estrogen and progesterone can help cancer cells grow more quickly than normal (especially estrogen).
The aim of hormone therapy is therefore to reduce the concentration of estrogen in the body so that these hormones don't join together with the cancer cells and also to reduce the risk of cancer coming back in the breast (and protecting the other breast). This therapy should be followed for a few years.
The type of hormone therapy will depend on whether or not you have gone through menopause and the risk of the tumor coming back.
After menopause,the ovaries stop producing estrogen. If you are in this phase, your doctor may recommend that you take some of these drugs: anastrozole, letrozole, or exemestane. Your doctor may prescribe tamoxifen together with some of the aforementioned drugs, or simply tell you to take tamoxifen alone.
Before menopause,the ovaries are producing estrogen. If you are in this phase, your doctor may prescribe the following medication: tamoxifen, goserelin (this makes the ovaries stop producing estrogen), or a combination of the two.
Hormone therapies may produce early or permanent menopause. If you are premenopausal, your doctor may recommend that you have a bone density scan to check on your bones. In order to prevent osteoporosis, your doctor will prescribe bisphosphonate or calcium supplements.