Neoadjuvant endocrine therapy in breast cancer

Summary The clinical benefits of endocrine therapy for patients with hormonosensitive breast cancer are well established. For many years, five years’ treatment with tamoxifen was the gold standard of adjuvant treatment. The recent development of new endocrine agents provides physicians with the opportunity to take a more effective therapeutic approach. Nevertheless, the success of neoadjuvant endocrine therapy is much more recent and less frequently reported in the literature. This article reviews the studies published on neoadjuvant endocrine treatment (tamoxifen and aromatase inhibitors). According to the literature, neoadjuvant endocrine therapy seems to be effective and well tolerated. The newer generation of aromatase inhibitors (letrozole, anastrozole, exemestane) appear to result in better overall response rates and more conservative surgery than tamoxifen. Patients with an ER Allred score of 6 and over are most likely to respond and gain clinical benefit. The optimal duration of neoadjuvant therapy has not yet been investigated in detail. These preliminary results are interesting and should be confirmed by further studies.