Cost effectiveness of androgen suppression plus radiation therapy for clinically localized prostate cancer.

6010 Background: In addition to studying traditional clinical outcomes, examination of both quality of life and economic outcomes of new treatment regimens is warranted, particularly for those that may be considered expensive and/or associated with significant toxicities. We constructed a model to predict long-term quality-adjusted outcomes and cost-effectiveness of adding androgen suppression therapy (AST) to radiotherapy (RT) for clinically localized prostate cancer.,Based on 5-yr clinical trial data from D'Amico, et al. (JAMA 2004; 292(7):821-827), we constructed a Markov process to compare outcomes for RT alone vs. RT plus 6 mos of AST, for pts with clinically localized prostate cancer. Quality-of-life utility measures and cost data were obtained from published literature. We included costs associated with hormone treatment, toxicity, and disease progression. The analysis was performed from the health care payer perspective, with results reported in 2004 U.S. dollars. A 15-yr time horizon and 3% discount rate were used, and one-way sensitivity analyses were performed. Since optimal AST duration is still unclear, we also analyzed the effects of increasing AST duration.,The projected 15-yr progression-free survival was 33% vs. 11%, for RT+AST vs. RT, respectively, while the projected 15-yr overall survival was 52% vs. 26%. At 15 years, the RT+AST group showed a net gain of 1.65 quality-adjusted life years (QALYs) and no net cost compared with RT alone (total costs $15,000 for RT+AST vs. $15,500 for RT alone). Results were most sensitive to changes in time horizon, discount rate, and utility for progression. At time horizons of greater or less than 15 years, the incremental cost-effectiveness ratio (ICER) was positive, but never more than $6500/QALY. If AST treatment duration was extended to 3 years, the 15-yr gain in QALYs was 1.58 and the ICER was $7400/QALY.,The addition of AST to RT for the treatment of clinically localized prostate cancer is cost effective over a wide range of parameters. The magnitude of the cost-effectiveness is highly dependent upon time horizon. No significant financial relationships to disclose.