Hormone Therapy for Breast Cancer
What Is Hormone Therapy?
Hormones are chemicals produced by glands in the body
and are circulated in the blood. Hormone therapy -- also called hormonal
therapy, hormone treatment, or endocrine therapy -- is any treatment that adds,
blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to boost low
hormone levels. Sometimes, hormone therapy is used to slow or stop the growth
of certain cancers (such as prostate
and breast cancer). The female
and progesterone, for example, promote the growth of some breast cancer cells. So hormone therapy may be
given to block the body's naturally occurring estrogen and fight the cancer's
growth. Sometimes surgery is needed to remove the source of the hormone in
question -- in the case of breast cancer, the ovaries may be
When Is It Used to Treat Breast Cancer?
Hormone therapy is used in women with
breast cancer whose tumors are sensitive to the hormones estrogen or
progesterone (meaning that hormones cause the cancer to grow). Not all breast
cancers are hormone sensitive, so not all breast cancers will respond to a
The drugs slow or stop the growth of cancer cells that are
present in the body. As an adjuvant (add-on) therapy, hormone therapy helps
prevent the original breast cancer from returning and also helps prevent the
development of new cancers in the other breast.
Women at an increased risk of developing
breast cancer (those with a genetic predisposition or family history) have the
option of taking hormone therapy to reduce their chance of ever developing the
What Are Common Hormone Drugs Used for Breast Cancer?
Tamoxifen.The gold standard of hormone therapy in breast cancer is
tamoxifen, marketed as Nolvadex, a
drug in pill form that interferes with the activity of estrogen. Known as the
"antiestrogen," tamoxifen is a pill that has been used for more than 30 years
to treat patients with advanced (metastatic or stage IV) breast
Tamoxifen is also used as additional
therapy following surgery for early (stages I and II) and locally advanced
(stage III) breast cancer and as a means of reducing the risk of ever
developing breast cancer among women at particularly high risk (those with a
genetic predisposition to and a family history of the disease). Tamoxifen is
useful in both premenopausal and postmenopausal women.
Tamoxifen is also used to treat men with
Arimidex and Femara.
The most well known of these drugs, Arimidex and Femara, belong to a class of
medications known as aromatase inhibitors. After menopause, a woman's main
source of estrogen comes through a process called aromatization, in which male
hormones called androgens (produced by the adrenal glands located at the top of
the kidneys) are converted into estrogen. This process takes place throughout
the body, in the fatty tissue. These drugs fight tumor growth by stopping the
conversion of androgens into estrogen.