The benefits, harms, and cost-effectiveness of age-based and risk-stratified screening for prostate cancer with MRI

BackgroundProstate cancer screening with MRI may lead to lower overdiagnosis by detecting fewer insignificant cancers. However, the balance of benefits and harms, as well as the cost-effectiveness of MRI-based prostate cancer screening under different strategies remains uncertain. The aim of this simulation study was to assess MRI-based prostate cancer screening under both age-based and risk-based screening strategies. MethodsWe used a life-table model to simulate men aged 55 to age 89 under age-based and polygenic risk-based screening strategies using either screening MRI or PSA as the primary screening test. We conducted extensive scenario, threshold, and sensitivity analyses to determine the robustness of conclusions to input parameters. Primary outcomes were prostate cancer deaths, overdiagnosed cancers, resource use, and cost-effectiveness (net health benefit from a healthcare perspective). ResultsMRI screening every 4 years from 55 to 69 years old could reduce overdiagnosis by 42.1% (95% intervals: 19.5%-60.5%) in comparison to a PSA-based screening programme. We estimated that MRI screening would lead to 12 (95% intervals: 7-19) overdiagnosed cancers per 1,000 men screened compared with 21 (95% intervals: 14-29) with PSA screening. All MRI screening strategies generated more quality-adjusted life-years (QALYs) and fewer costs than PSA screening. For age-based MRI screening to have a greater net health benefit (NHB) than no screening would require a willingness-to-pay (WTP) of {pound}119,000 per quality-adjusted life-year (QALY) gained. Risk-stratified MRI screening strategies were more likely to be cost-effective, generate more QALYs, and lead to fewer overdiagnosed cancers than screening all men. At a WTP of {pound}30,000 per QALY gained, MRI screening of men aged 55 with a 10-year absolute risk of prostate cancer of [≥]6.4% had a greater NHB than no screening; the most cost-effective strategy at this WTP threshold was MRI screening at a 10-year absolute risk threshold of [≥]8.5%. Results were sensitive to assumptions regarding the mean sojourn time - the mean time cancers are screen-detectable but pre-clinical - and the relative mortality benefits of screening strategies. ConclusionMRI based screening could reduce overdiagnosis and prove more cost-effective than PSA-based screening. Risk-stratified strategies are likely to be necessary for a prostate cancer screening programme to be considered cost-effective in the UK.