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 e 36 000. 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 e 41 500. 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.