Trastuzumab treatment of early stage breast cancer is cost-effective from the perspective of the Belgian health care authorities

Trastuzumab (Herceptin, Roche) is a recombinant, humanized monoclonal antibody directed against the neu-HER2 protein, since May 2002 reimbursed in Belgium for the treatment of metastatic HER2+ breast cancer and since June 2007 also in adjuvant therapy of HER2+ early stage breast cancer. The purpose of this study was to estimate the cost-effectiveness from the Belgian health care payer perspective of reimbursing trastuzumab in the latter indication.A Markov state transition model was designed to adequately capture the natural history and course of disease for early stage breast cancer patients, and to simulate cost and disease progression over a life time perspective. The model estimates differences in outcomes for patients treated with adjuvant trastuzumab during 1 year compared to current therapy, and captures cost consequences and health benefits of trastuzumab treatment. Health benefits were expressed in terms of quality-adjusted life years gained, and future benefits were discounted at 1.5%. Costs were calculated from the perspective of the Belgian authorities' health care budget, and future costs were discounted at 3%. Where relevant, the costs per Markov state were obtained from the IMS Hospital Disease database. Additionally, an expert opinion analysis on resource use during the follow-up of treated early breast cancer patients provided the cost estimates for states with minor or without hospital costs.The incremental cost-effectiveness ratio based on a life time simulation was estimated at 10,315 per quality-adjusted life year gained. It can be concluded that trastuzumab treatment of HER2+ early stage breast cancer patients is cost-effective from the perspective of the Belgian health care authorities.