Cost-effectiveness of 3-year vs 1-year adjuvant therapy with imatinib in patients with high risk of gastrointestinal stromal tumour recurrence in the Netherlands; a modelling study alongside the SSGXVIII/AIO trial

AbstractBackground:Surgical resection of gastrointestinal stromal tumour (GIST) is rarely curative in patients at high risk of tumour recurrence and therefore 1 year of post-surgery adjuvant imatinib therapy has been recommended in this sub-group. Recently, adjuvant imatinib therapy administered for 3 years has been demonstrated to further increase recurrence-free survival and overall survival. The goal of this study was to assess the economic value of extending the duration of adjuvant imatinib therapy in high-risk patients in the Netherlands.Methods:A multistate Markov model was developed to simulate how patients’ clinical status after GIST excision evolves over time until death. The model structure encompassed four primary health states: free of recurrence, first GIST recurrence, second GIST recurrence, and death. Transition probabilities between the health states, data on medical care costs, and quality-of-life were obtained from published sources and from expert opinion.Results:The expected number of...