Adjuvant endocrine therapy: Controversies and perspectives

This is an exciting time in the treatment of hormone receptor-positive breast cancer as a number of new therapeutic options become available. Over the past two decades, tamoxifen, a selective estrogen receptor modulator (SERM), has been used to treat steroid receptorpositive breast cancer, either as a single agent or in conjunction with chemotherapy or ovarian ablation. As a result, a large amount of data has been generated with respect to its efficacy, safety, and toxicity. In summary, these aggregated data at 15 years follow-up show that women who took tamoxifen for 5 years as treatment for axillary lymph node-positive, estrogen receptor (ER)-positive breast cancer demonstrated an absolute improvement in survival of 12.6%.1 In women with node-negative disease this benefit in survival was 5.3%. These survival benefits were observed irrespective of menopausal status. In the year 2000, tamoxifen therapy was endorsed by the US Consensus Development Conference as standard treatment for virtually all women with hormone receptorpositive invasive breast cancer,2 a view shared by the St Gallen Conferences of 2001, 2003 and 2005.3,4 The long-term success of tamoxifen has led to the development of other SERMs and selective estrogen receptor destroyers (SERDs).