An economic evaluation was conducted comparing anastrozole, exemestane, letrozole and megestrol for the second-line treatment of postmenopausal patients with hormone-sensitive metastatic breast cancer who had failed tamoxifen.
An economic model was developed based on data from phase III megestrol-controlled clinical trials of antiaromatase agents (AA) and estimates of resource utilization from both Statistic Canada's Population Health Model for breast cancer and expert opinion.
In megestrol-controlled trials, anastrozole and exemestane equivalently improved survival compared to megestrol, while letrozole did not. Compared to megestrol, exemestane and anastrozole both cost Canadian $9000 per life-year gained, and letrozole saved Canadian $300 annually, with no life-year gain. Cost-effectiveness results were robust under sensitivity analysis testing. However, the model was dependent on any difference between AAs with respect to survival benefit and drug acquisition price.
Based on available data and this cost-effectiveness analysis, exemestane and anastrozole are appropriate choices for second-line hormonal treatment of metastatic breast cancer.