Background: Observation is underutilized among men with localized, low-risk prostate cancer.
Objective: To assess the costs and benefits of observation versus initial treatment.
Design: Decision analysis simulating treatment or observation.
Data Sources: Medicare schedules, published literature.
Target Population: Men aged 65 and 75 years who had newly diagnosed low-risk prostate cancer (prostate-specific antigen level <10 µg/L, stage ≤T2a, Gleason score ≤3 + 3).
Time Horizon: Lifetime.
Intervention: Treatment (brachytherapy, intensity-modulated radiation therapy, or radical prostatectomy) or observation (active surveillance [AS] or watchful waiting [WW]).
Outcome Measures: Quality-adjusted life expectancy and costs.
Results of Base-Case Analysis: Observation was more effective and less costly than initial treatment. Compared with AS, WW provided 2 additional months of quality-adjusted life expectancy (9.02 vs. 8.85 years) at a savings of $15 374 ($24 520 vs. $39 894) in men aged 65 years and 2 additional months (6.14 vs. 5.98 years) at a savings of $11 746 ($18 302 vs. $30 048) in men aged 75 years. Brachytherapy was the most effective and least expensive initial treatment.
Results of Sensitivity Analysis: Treatment became more effective than observation when it led to more dramatic reductions in prostate cancer death (hazard ratio, 0.47 vs. WW and 0.64 vs. AS). Active surveillance became as effective as WW in men aged 65 years when the probability of progressing to treatment on AS decreased below 63% or when the quality of life with AS versus WW was 4% higher in men aged 65 years or 1% higher in men aged 75 years. Watchful waiting remained least expensive in all analyses.
Limitation: Results depend on outcomes reported in the published literature, which is limited.
Conclusion: Among these men, observation is more effective and costs less than initial treatment, and WW is most effective and least expensive under a wide range of clinical scenarios.
Primary Funding Source: National Cancer Institute, U.S. Department of Defense, Prostate Cancer Foundation, and Institute for Clinical and Economic Review.