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 Euro 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.