Letrozole compared with anastrozole for breast cancer

23 January 2017


This Novartis Pharmaceuticals sponsored clinical trial looked at whether there is a difference between letrozole and anastrozole when treating early breast cancer.

Scientific Title

A randomised multi-centre phase IIIb, open-label study of Letrozole versus Anastrozole in the adjuvant treatment of postmenopausal women with hormone receptor and node-positive breast cancer (Study No. CFEM345D2411

Short Title

Femara versus Anastrozole Clinical Evaluation (FACE) trial


Almost 80% of all breast cancers are hormone receptor-positive.  Both letrozole and anastrozole are selective aromatase inhibitors (drugs that interfere with the making of oestrogens, one of the natural female hormones).  They have been widely used in post-menopausal patients with advanced hormone-sensitive cancer and will control disease in a proportion of patients.  They have also been used in post-menopausal women with early hormone-sensitive breast cancer and are more effective than tamoxifen in preventing recurrence after surgery. This trial assesses head to head the relative effectiveness of these two aromatase inhibitors and also to evaluate their benefit in higher-risk patients with node-positive disease (spread of cancer to the armpit lymph nodes).


Letrozole did not demonstrate significantly superior efficacy or safety compared with anastrozole in this clinical trial involving more than 4,000 patients worldwide.


Comparative Efficacy and Safety of Adjuvant Letrozole VersusAnastrozole in Postmenopausal Patients With Hormone Receptor-Positive, Node-Positive Early Breast Cancer: Final Results of the Randomized Phase III Femara Versus Anastrozole Clinical Evaluation (FACE) Trial. Ian Smith, Denise Yardley, Howard Burris, Richard De Boer et al. Journal of Clinical Oncology. 23 January, 2017 DOI: 10.1200/JCO.2016.69.2871

Sub-study Biomarker sub-study to the FACE trial

This exploratory research investigated how genes and proteins influence the different responses people have to the drugs anastrozole and letrozole.