Enhancing the adjuvant treatment of hormone receptor positive breast cancer.

Aromatase inhibitors (AIs) are now regarded as the optimum hormonal therapy for postmenopausal women with hormone receptor positive breast cancer. However, it is unclear which of the currently available AIs offers patients the most effective and the best-tolerated treatment strategy. We performed a systematic review and meta-analysis of randomized-controlled trials that compared AIs (as first-line agents) with standard hormonal treatment in patients with breast cancer. The results suggest that letrozole offers a more favorable side-effect profile particularly in terms of musculoskeletal adverse events. However, the available data suggests a small survival benefit from the use of anastrozole although patients treated with anastrozole appear to have a more favorable disease profile at study entry. Examination of survival data on adjuvant tamoxifen therapy from these trials supports this observation.