Patient-reported outcomes from MA.17R: A randomized trial of extending adjuvant letrozole for 5 years after completing an initial 5 years of aromatase inhibitor therapy alone or preceded by tamoxifen in postmenopausal women with early-stage breast cancer.

LBA506 Background: MA.17R is a Canadian Cancer Trials Group (CCTG) led phase III randomized controlled trial comparing letrozole to placebo after 5 years of aromatase inhibitor (AI) as adjuvant therapy for hormone-receptor positive breast cancer. The primary endpoint was disease-free survival. Quality of life (QOL) was a secondary endpoint. Methods: QOL was measured with the SF-36 (2 summary scores and 8 domains) and …