PURPOSE - Combined androgen blockade therapy (CAB) has been shown to have a small survival advantage over luteinizing hormone releasing hormone LH-RH agonists (LH-RHa) alone in men with metastatic prostate cancer. The goal of this study was to assess the cost-effectiveness of CAB with bicalutamide and LH-RH agonist therapy to LH-RH agonist therapy alone.
MATERIALS AND METHODS - A macro-simulation model was developed to compare the cost-effectiveness of 2 interventions for stage D2 prostate cancer, 1) CAB with bicalutamide 50 mg per day and monthly dosing of an LH-RHa or 2) monthly LH-RH agonist therapy. Cost and outcomes are tabulated in 5 and 10-year time horizons. Model assumptions were taken from the published literature. Appropriate 1-way and multi-way sensitivity analyses were performed.
RESULTS - At 5 years, the incremental cost-effectiveness ratio (ICER) for CAB, when compared with LH-RHa monotherapy, was US dollars 33,677 per quality-adjusted life-year. In other words, for every additional quality-adjusted life year that a patient lived because he received CAB, it cost US dollars 33,677. At 10 years the ICER for CAB was US dollars 20,053 (well within the accepted cost-effectiveness threshold). If quality adjustment was not included, the ICER for CAB was even more favorable (US dollars 20,489 at 5 years and US dollars 13,313 at 10 years). The model was most sensitive to the estimates of effectiveness (survival) of LH-RHa therapy alone and CAB therapy. The model was also fairly sensitive to the quality of life effect of having late stage prostate cancer and the cost of bicalutamide.
CONCLUSIONS - CAB with bicalutamide is cost-effective when compared with LH-RH monotherapy in men with stage D2 prostate cancer.