Tamoxifen is one of the most effective medications given to pre-menopausal patients to decrease their risk of recurrence of metastatic cancer. This anti-hormone therapy drug reduces their risk by about 50 percent, and is one of the most effective methods of breast cancer hormone therapy available.
Most patients tolerate the drug well, but side effects including hot flashes, insomnia, weight gain and mood changes that may occur initially. These side effects 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 work to stop a key enzyme called aromatase from changing other hormones into estrogen. Arimidex, Femara or 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 percent. They do not increase the risk of uterine cancer or cataracts, but can worsen menopausal symptoms such as hot flashes. These drugs can increase the formation of blood clots, cause bone pain, and worsen osteoporosis. Most patients tolerate the drugs well. Ten years is the recommended duration of treatment.
Evista is a drug proven to decrease the risk of recurrent or metastatic breast cancer in post-menopausal patients about the same as Tamoxifen, i.e., 50%. Unlike the aromatase inhibitors, Evista strengthens bones, rather than promoting osteoporosis. Because it is less effective, it is a second or third-line medication in post-menopausal women who do not tolerate the other medications.