Cost-effectiveness of extended adjuvant letrozole therapy after 5 years of adjuvant tamoxifen therapy in postmenopausal women with early-stage breast cancer.

Objective: To estimate the cost-effectiveness of extended adjuvant letrozole in postmenopausal women with early breast cancer and estrogen or progesterone receptor-positive tumors who had completed 5 years of adjuvant tamoxifen.

Study Design: Cost-effectiveness analysis using a Markov model.

Methods: Using a Markov model, we estimated the incremental cost per quality-adjusted life-year (QALY) gained with extended adjuvant letrozole vs no extended adjuvant therapy.