Cost Effectiveness of Adjuvant Trastuzumab in Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer

Abstract
Purpose To evaluate the cost-effectiveness of 12-month adjuvant trastuzumab therapy in women with high-risk human epidermal growth factor receptor 2 (HER2) –positive early breast cancer. Methods A Markov model tracked quarterly patients’ transitions between five health states: disease free, local relapse, disease free after local relapse, metastatic disease, and death. Patients were allowed to incur symptomatic or asymptomatic transient cardiac dysfunction during trastuzumab administration. Probabilities were derived mainly from the combined report of the National Surgical Adjuvant Breast and Bowel Project B-31 and the North Central Cancer Treatment Group N9831 trials (95% node positive) and a meta-analysis by the Early Breast Cancer Trialists’ Collaborative Group. Costs were estimated from the perspective of the Italian and US health care systems. The analysis was run during a 15-year time horizon. A 3% yearly discount rate was applied to both costs and life-years. Second-order Monte-Carlo and probabilis...