Patient-reported outcomes with anastrozole versus tamoxifen for postmenopausal patients with ductal carcinoma in situ treated with lumpectomy plus radiotherapy (NSABP B-35): a randomised, double-blind, phase 3 clinical trial

Summary Background The NSABP B-35 trial compared 5 years of treatment with anastrozole versus tamoxifen for reducing subsequent occurrence of breast cancer in postmenopausal patients with ductal carcinoma in situ. This report assesses the effect of these drugs on quality of life and symptoms. Methods The study was done at 333 hospitals in North America. Postmenopausal women with hormone-positive ductal carcinoma in situ treated by lumpectomy with clear resection margins and whole breast irradiation were randomly assigned to receive either tamoxifen (20 mg/day) or anastrazole (1 mg/day) for 5 years, stratified by age (