Adjuvant tamoxifen: how long before we know how long?

Despite recent advances, we still need more information from large clinical trials to define the optimum duration of tamoxifen treatment after surgery for breast cancer. Tamoxifen is the most widely prescribed and arguably the most important anticancer drug in clinical use. It has been established beyond doubt that adjuvant tamoxifen after primary treatment for early breast cancer improves survival. 1 2 Tamoxifen also reduces the incidence of second primary breast cancers, 1 2 preserves bone mineral density,3 and may lower the incidence of coronary heart disease.4 Although tamoxifen is generally well tolerated, it can produce menopausal symptoms and, on occasion, it has serious side effects, including an increased risk of endometrial carcinoma. 1 2 However, the benefits of a few years of adjuvant tamoxifen treatment clearly outweigh the risks, and its widespread adoption is considered the major contributor to the recent fall in mortality from breast cancer in the United Kingdom.5