The adjuvant Femara versus Anastrozole Clinical Evaluation (FACE) trial compares upfront therapy letrozole 2.5 mg with anastrozole 1 mg daily for up to 5 years in postmenopausal, hormone receptor-positive, node-positive breast cancer patients. This phase III b open label, randomized, multicenter study will include 4000. patients from up to 250 international sites. Patients will be stratified by degree of lymph node involvement and HER-2 status. Any efficacy and safety difference of the two drugs will be reported. Primary objective is DFS, secondary objectives are safety, OS, time to distant metastases, time to contralateral breast cancer and breast cancer specific survival.