How long should a patient take tamoxifen for the treatment of breast cancer?
Patients with metastatic breast cancer may take tamoxifen for varying lengths of time, depending on the cancer’s response to this treatment and other factors. When used as adjuvant therapy for early-stage breast cancer, tamoxifen is generally prescribed for 5 years. However, the ideal length of treatment with tamoxifen is not known. Two studies have confirmed the benefit of taking adjuvant tamoxifen daily for 5 years. When taken for 5 years, tamoxifen reduces the chance of the original breast cancer coming back in the same breast or elsewhere. It also reduces the risk of developing a second primary cancer in the other breast. Clinical trials are ongoing to determine whether hormone therapy taken for more than 5 years is beneficial. These studies usually include aromatase inhibitors (AIs) (another type of antiestrogen) (see Question 15). For example, the National Cancer Institute (NCI), a part of the National Institutes of Health, is sponsoring the National Surgical Adjuvant Breast and
