OBJECTIVES - To determine the cost-effectiveness of combined androgen blockade (CAB) with bicalutamide versus CAB with flutamide in men with Stage D2 prostate cancer. Both bicalutamide and flutamide are commonly used in CAB for prostate cancer. Although the cost of bicalutamide is more than that of flutamide, it is important that the efficacy, quality of life, and side effects are also considered when determining whether CAB with bicalutamide is a cost-effective option.
METHODS - A decision model was created to compare treatment strategies. Survival and side-effect information was based on a randomized trial that directly compared bicalutamide and flutamide. The costs and quality-of-life effects related to therapy were determined from published sources.
RESULTS - The incremental cost per quality-adjusted life year gained for bicalutamide versus flutamide was 22,000 dollars and 16,000 dollars at 5 and 10 years, respectively. If a quality adjustment was not included, the incremental cost-effectiveness ratio for CAB with bicalutamide compared with CAB with flutamide was even more favorable (20,000 dollars/life year gained at 5 years). One-way sensitivity analysis demonstrated that the cost-effectiveness estimates were most sensitive to drug costs and survival (baseline survival was not significantly different between therapies). Multi-way uncertainty analysis revealed that the median value of the incremental cost-effectiveness ratio at 5 years was 13,637 dollars/quality-adjusted life year when all the parameters were varied over a clinically reasonable range.
CONCLUSIONS - Bicalutamide is cost-effective compared with flutamide when used for androgen blockade as part of CAB for men with advanced prostate cancer.