Early recurrence risk: aromatase inhibitors versus tamoxifen

Abstract

Aromatase inhibitors (AIs) are becoming the hormonal treatment of choice for postmenopausal women with early breast cancer. Large, well-controlled clinical studies have established the efficacy and safety of initial adjuvant therapy with letrozole or anastrozole versus the previous standard of 5 years of adjuvant tamoxifen and support using an AI (exemestane, anastrozole or letrozole) following tamoxifen for 2–3 years (early ‘switch’ treatment) or 5 years (extended adjuvant treatment). Reducing recurrence risk is a primary goal of adjuvant hormonal therapy. There is an early peak of recurrences 2 years after surgery; most are distant metastases rather than local or regional events. Therefore, treatment strategies such as initial therapy with AIs, which reduce early distant recurrence events, can be expected to improve long-term survival outcomes. Switching to an AI following 2–3 years of initial adjuvant tamoxifen is an effective option for patients unable to begin treatment with an AI.

Keywords::

• anastrozole
• aromatase inhibitor
• distant metastases
• early breast cancer
• exemestane
• letrozole

Acknowledgements

The authors thank Maria Soushko of Phase Five Communications, Inc. for medical editorial assistance with this manuscript.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing assistance was utilized in the production of this manuscript. Financial support for medical editorial assistance was provided by Novartis Pharmaceuticals.