Breast Cancer Hormone Therapy   

In some types of cancers such as breast cancer and prostate cancer, the cancer cells depend on hormones to multiply; these types of cancers are called hormone-dependent cancers. Therefore, to stop the proliferation of the cancerous cells, your doctor may recommend you take drugs capable of blocking hormonal stimulation. Along with chemotherapy or radiotherapy, hormone therapy (HT) is commonly used to fight breast cancer; results vary from one patient to another. In general, hormone therapy is less toxic, and causes fewer side effects than chemotherapy.  

However, this therapy cannot be used in all types of breast cancer. Some young and pre-menopause women sometimes have cancers that are not hormone receptors; the cancer cells are not sensitive to hormone therapy.   

In the treatment of breast cancer, hormone therapy may include two groups of drugs: selective estrogen receptor modulators (SERMs) and aromatase inhibitors. 

Selective estrogen receptor modulators (SERMs): this class of drugs acts by blocking the action of estrogen in breast tissue, thus preventing breast cancer cells to multiply. These drugs act like estrogen on some cells (by stimulating the estrogen receptors), while blocking the effects of estrogen on other cells (by inhibiting the estrogen receptor). SERM has a preventive and curative effect against breast cancer; it kills cancer cells and reverses the growth of the tumor. 

Tamoxifen is one of the SERM which has revolutionized the hormonal treatment of breast cancer. It can be used in the prevention and treatment of breast cancer. Raloxifene is another SERM drug group and has characteristics similar to tamoxifen. However, it has a half-life much shorter than tamoxifen and should be used in higher dose.  

Some side effects of s elective estrogen receptor modulators may include: n ight sweats; water retention; weight loss; irregular menstrual periods; hot flashes; or/and vaginal itching, discharge or dryness. 

Older women may experience serious complications such as bone pain, back pain, headaches, cough, high cholesterol, blood clots, or endometrial cancer.  

Aromatase inhibitors: aromatase inhibitors are a recent class of drugs used in hormone therapy to treat breast cancer in menopausal women. They act by reducing estrogen levels in the blood of postmenopausal women. They inhibit or inactivate aromatase, an enzyme responsible for the synthesis of estrogens from androgens of adrenal origin. Unlike tamoxifen, users of aromatase inhibitors may experience one negative effect, increased risk of osteoporosis; they generally are well tolerated by most women. The most common aromatase inhibitors are anastrozole (Arimidex), letrozole (Femara) and exemestane (Aromasin).