Comparison Trial of Letrozole to Anastrozole in the Adjuvant Treatment of Postmenopausal Women With Hormone Receptor and Node Positive Breast Cancer

Eligible patients will be post-menopausal hormone receptor- and lymph node-positive females who recently underwent primary surgery for breast cancer. Patients will be randomized to letrozole (2.5 mg per day for 5 years) vs anastrozole (1 mg per day for 5 years). Follow up will occur for 5 years after the completion of enrollment for survival and disease status updates.