ABSTRACT
The introduction of aromatase inhibitors (AI) has resulted in practice change approaches in the treatment of early breast cancer. In this paper, we analyze the most relevant studies including the ATAC, BIG 1-98, TEAM, MA-17, NSABP B-33, and ABSCG-6 studies. Postmenopausal patients with hormone receptor-positive early breast cancer should be treated with AI for 5 years. For patients who have been initiated with tamoxifen (TAM), switching to an AI to complete 5 years of treatment is also recommended. The results of the extended adjuvant therapy studies recommend the use of an AI (anastrozole, letrozole, or exemestane) after the completion of standard TAM treatment. With regards to premenopausal women, TAM is the recommended adjuvant hormonal treatment for pre- and perimenopausal women. There is no indication for the use of AI in these subgroups of patients. Finally, determination of CYP 2D6 polymorphisms could be considered when choosing the best adjuvant hormonal treatment option.