Cost-effectiveness of Extended Adjuvant Letrozole Therapy After 5 Years of Adjuvant Tamoxifen Therapy in Postmenopausal Women With Early-stage Breast CancerByThomas E. Delea, MSIA,Jonathan Karnon, MSc, PhD,Robert E. Smith, MD,Stephen R. D. Johnston, MD, PhD, FRCP,Jane Brandman, BPharm, MS,Jennifer C. Y. Sung, PharmD,Paul E. Goss, MD, PhD, FRCPC, FRCP(UK)July 15th 2006