Cost-effectiveness of HER2 testing and 1-year adjuvant trastuzumab therapy for early breast cancer.

BACKGROUND Clinical studies have demonstrated statistically significant reduction of breast cancer relapse and improved overall survival by adding trastuzumab for 1 year after adjuvant chemotherapy in human epidermal growth factor receptor-2 protein (HER2)/neu-positive breast cancer. The aim of this study was to analyze the cost-effectiveness of HER2/neu testing and the addition of 1-year adjuvant trastuzumab after adjuvant chemotherapy from a societal perspective in a Swedish setting. MATERIAL AND METHODS We used a Markov state transition model to simulate HER2/neu testing and adjuvant trastuzumab treatment in a hypothetical cohort of early breast cancer patients. RESULTS The cost per quality adjusted life year (QALY) gained for immunohistochemical (IHC) testing for all patients with FISH confirmation of IHC 2+ and 3+ and 1-year adjuvant trastuzumab for FISH-positive patients was estimated to 36,000 euros. The strategy of FISH testing for all patients, with 1-year adjuvant trastuzumab for FISH-positive patients was associated with the longest quality adjusted survival of all evaluated treatment strategies and the cost per QALY gained was estimated to 41,500 euros. The remaining testing and treatment strategies were dominated. CONCLUSION FISH testing for all patients with 1-year adjuvant trastuzumab for FISH+ patients is a cost-effective treatment option from a societal perspective.