Antiaromatase agents: evolving role in adjuvant therapy.

The goal of adjuvant hormonal therapy is to prevent breast cancer recurrence. Standard therapy with tamoxifen has shown great value in the adjuvant setting; however, its tolerability profile can render it unsuitable for some patients. The aromatase inactivator, exemestane, and the 2 aromatase inhibitors, letrozole and anastrozole, have been shown to be equivalent or superior to tamoxifen with respect to multiple endpoints in patients with metastatic breast cancer. With tolerability profiles that are similar to, and in many cases, more acceptable than that of tamoxifen, and efficacy potentially superior to tamoxifen, studies using the antiaromatase agents as adjuvant therapy are currently ongoing. These trials will answer some important questions, such as the order in which adjuvant hormonal therapies are selected to maximize efficacy, whether the antiaromatase agents show improved tolerability, and whether combination therapy is more effective than monotherapy.