The AI War is Over: It's a Tie

The use of aromatase inhibitors (AIs) as adjuvant therapy for postmenopausal women with hormone-sensitive breast cancer is well established. For a decade, large, randomized clinical trials were conducted to demonstrate that AIs were better than tamoxifen (modestly) for this population of patients. In addition, comparisons were made to determine whether one AI was superior, in terms of efficacy or tolerability, among the three commercially available agents: steroidal exemestane and nonsteroidal anastrozole and letrozole. Guideline committees, initially rigid in their recommendations about which AIs should be used, eventually concluded that there were no material differences among the three drugs.

To examine this issue further, investigators c…