Adjuvant trials: Aromatase inhibitors in early breast cancer – Are they alike?

Summary fen has been a standard therapy for breast cancer, but its use is complicated by serious events, including endometrial cancer and thromboembolism. Tamoxifen therapy beyond the recommended 5 years fails to improve disease outcomes, leaving many patients without a treatment option and susceptible to relapse. While all third-generation aromatase inhibitors have proven to be more effective than tamoxifen in reducing recurrence risk, in a variety of settings, there may be some differences in efficacy. For example, there is evidence that letrozole is the most potent suppressor of estrogen levels, and this may translate to greater clinical efficacy. Indeed, letrozole has been consistent at improving outcomes and is approved in a range of treatment settings, including extended adjuvant therapy, where tamoxifen is not indicated, and more recently, in the early adjuvant setting in the United States and Europe. While other potential long-term complications of aromatase inhibitor therapy will require further study, bone loss appears manageable through bisphosphonate therapy. Results of trials currently under way should determine the optimal use of the aromatase inhibitors in breast cancer therapy.