Aromatase inhibitors in adjuvant setting in breast cancer

For more than twenty years, tamoxifen represents the gold standard treatment in adjuvant setting for breast cancer patients. However, the tamoxifen activity remains complex, with its agonist effects, sometimes a poor tolerance and a certain number of patients become refractory to treatment. The aromatase inhibitors, such as progestatifs, were developed to challenge tamoxifen efficacy, along with improved tolerability. The third generation of aromatase inhibitors seems to provide significant gains in efficacy over tamoxifen for postmenopausal patients with hormone receptor positive breast cancer and they have already been approved in patients with metastatic disease. We review, in this article, the rationale for using IA in patients with breast cancer and, across the different clinical trials results already published, their current major role they are playing in adjuvant setting for menopausal hormonal receptor-positive breast cancer patient. One of the main issues using the third generation of IA is their long-term side effects, especially bone turnover and lipid metabolism.