Anti-Hormone Therapy

Most breast cancers have estrogen receptors, which respond well to breast cancer hormone therapy. At our center in Beverly Hills, we use anti-hormone drugs to prevent cancer cells from reproducing. Estrogen promotes this growth, and anti-hormone drugs are effective in blocking the receptors in the cancer cells.

Breast Cancer Hormone Therapy Options

Tamoxifen

Tamoxifen is one of the most effective medications given to pre-menopausal patients to decrease their risk of metastatic cancer recurrence. This anti-hormone therapy drug reduces their risk by about 50% and is one of the most effective methods of hormone therapy available for breast cancer treatment.

Most patients tolerate the drug well. However, you may experience initial side effects such as hot flashes, insomnia, weight gain, and mood changes. These side effects should lessen or resolve with time. Other complications include blood clots (deep vein thrombosis or pulmonary embolism), cataracts, and uterine cancer. These problems are rare in most patients but will be monitored by an oncology specialist. Recent studies have demonstrated that patients do better if they maintain an anti-hormone therapy treatment plan for 10 years instead of the traditional 5-year period.

Aromatase Inhibitors

Aromatase inhibitors stop a key enzyme called aromatase from changing other hormones into estrogen. Arimidex, Femara, and Aromosin are anti-hormone therapy medications given to post-menopausal patients because they are more effective than Tamoxifen. This breast cancer hormone therapy reduces the rate of recurrence and metastatic disease by 70%. These medications do not increase the risk of uterine cancer or cataracts but can worsen menopausal symptoms, such as hot flashes. They can increase the formation of blood clots, cause bone pain, and worsen osteoporosis. However, most patients tolerate the drugs well. Ten years is the recommended duration of treatment.

Evista

Evista is a drug proven to decrease the risk of recurrent or metastatic breast cancer in post-menopausal patients to about 50%—similar to Tamoxifen. Unlike the aromatase inhibitors, Evista strengthens bones rather than promoting osteoporosis. Because it is less effective than other drugs, it is a second or third-line medication in post-menopausal women who do not tolerate the other medications. Learn more about Evista at fda.gov.