Trastuzumab in adjuvant breast cancer therapy. A model based cost-effectiveness analysis.

Trastuzumab has shown activity in early breast cancer patients that overexpress HER2. Significant resources have to be allocated to finance this therapy, underlining the need for cost-effectiveness analysis. A model was set up, societal costs were calculated and the discount rate was 3%. Life expectancy data were based on the literature and prolonged according to qualified guess (10% and 20% absolute improvement in overall survival (OS)). The comparator was the FEC(100) regimen. The median additional health care cost per patient treated was 33,597 euros. The yielding cost per life year gained (LYG) was 15,341 euros with a 20% improved OS and 35,947 euros with 10% improved OS. The corresponding net health care cost per quality adjusted life year (QALY) was 19,176 euros and 44,934 euros. Including all resource use the figures were 8148 euros and 30,290 euros per LYG. Sensitivity analyses documented survival gain, price of trastuzumab, production gain and discount rate to be the major factors influencing cost-effectiveness ratio. Trastuzumab is indicated cost effective in Norway.