Cost-effectiveness of prostate cancer screening: a simulation study based on ERSPC data

Abstract

Background: The results of the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial showed a statistically significant 29% prostate cancer mortality reduction for the men screened in the intervention arm and a 23% negative impact on the life-years gained because of quality of life. However, alternative prostate-specific antigen (PSA) screening strategies for the population may exist, optimizing the effects on mortality reduction, quality of life, overdiagnosis, and costs.

Methods: Based on data of the ERSPC trial, we predicted the numbers of prostate cancers diagnosed, prostate cancer deaths averted, life-years and quality-adjusted life-years (QALY) gained, and cost-effectiveness of 68 screening strategies starting at age 55 years, with a PSA threshold of 3, using microsimulation modeling. The screening strategies varied by age to stop screening and screening interval (one to 14 years or once in a lifetime screens), and therefore number of tests.

Results: Screening at short intervals of three years or less was more cost-effective than using longer intervals. Screening at ages 55 to 59 years with two-year intervals had an incremental cost-effectiveness ratio of $73000 per QALY gained and was considered optimal. With this strategy, lifetime prostate cancer mortality reduction was predicted as 13%, and 33% of the screen-detected cancers were overdiagnosed. When better quality of life for the post-treatment period could be achieved, an older age of 65 to 72 years for ending screening was obtained.

Conclusion: Prostate cancer screening can be cost-effective when it is limited to two or three screens between ages 55 to 59 years. Screening above age 63 years is less cost-effective because of loss of QALYs because of overdiagnosis.

Figure 1.

Prostate cancer develops from no prostate cancer via one or more screen-detectable preclinical stages to a clinically diagnosed cancer or screen-detected cancer. The arrows indicate the possible transitions. Each state can be local or metastatic, but for simplicity this is not illustrated. G = Gleason score; T = tumor stage.

Figure 2.

Net costs and (A) life-years gained or (B) quality-adjusted life-years gained (all 3.5% discounted) per 1000 men, of PSA screening strategies varying by interval and end age. The screens start at age 55 years, except for the once in a lifetime screens. At some points in the figure, the end ages are indicated. The efficient strategies in Figure 2B are connected by the efficient frontier (Eff frontier, solid curve) and are presented in Table 3. Strategies below this line are less cost-effective. Costs are in 2008 US dollars. QALY = quality-adjusted life-year.

Figure 3.

The annual death rate per 1000 men by age in the absence of screening as well as in the presence of screening from age 55 to 59 years with two-year intervals.