MRI-first prostate cancer screening cost-effective with benefits

An MRI-first diagnostic pathway, combined with risk-tailored screening, is shown to improve the benefit-to-harm profile and cost-effectiveness of screening for prostate cancer (PCa), according to results of a recent lifetable modelling study presented at AACR 2020 Virtual Meeting II.

In a recent systemic review and meta-analysis, an MRI pathway (ie, multiparametric MRI ± MRI-targeted prostate biopsy) demonstrated the most favourable diagnostic accuracy for detection of clinically significant PCa among various diagnostic strategies considered. [Cochrane Database Syst Rev 2019;18:e728-e729]

Comparing between the MRI pathway vs template-guided prostate biopsy and systemic prostate biopsy vs template-guided prostate biopsy, the MRI pathway demonstrated greater test sensitivity whilst maintaining a similar level of specificity (pooled sensitivity, 0.72 vs 0.63) (pooled specificity, 0.96 vs 1.00), with a pooled detection ratio of 1.12 in a mixed population of biopsy-naïve and previously biopsy-negative men.

In the current study, projecting age-specific PCa incidence and mortality, a hypothetical cohort of 4.48 million PCa-free men (age, 55–69 years) in the UK were simulated to receive no PCa screening, age-based screening (ie, quadrennial prostate-specific antigen [PSA] testing at 55–69 years of age), or risk-tailored screening (ie, quadrennial PSA testing if the 10-year absolute risk threshold was reached based on age and polygenic profile before the age of 70 years) strategies using biopsy-first and MRI-first diagnostic pathways. [Callender T, et al, AACR 2020 Virtual Meeting II, abstract 4758; PLOS Med 2019, doi: 10.1371/journal.pmed.1002998]

Polygenic risk was calculated from known risk susceptibility loci, with the 10-year absolute risk varying between 2 percent and 10 percent.

Trade-offs of benefit and harm were compared among different screening strategies, while cost-effectiveness analysis from a health service perspective was assessed at a discounted rate of 3.5 percent per annum.

“Compared with age-based screening, an MRI-first diagnostic pathway led to a 13.8 percent and 26.0 percent reduction in the number of overdiagnosed PCa cases and unnecessary biopsies, respectively, whilst preventing 1.8 percent more deaths from PCa, leading to greater quality-adjusted life-years [QALYs] gains and a 8.4 percent lowering in screening cost,” the researchers reported. “These gains necessitated a 3.7-fold increase in the number of MRI scans performed in an age-based screening programme.”

“The risk-tailored screening strategy vs age-based screening strategy, both using an MRI-first diagnostic pathway, demonstrated a further 10.5–71.3 percent and 22.9–57.3 percent reduction in the number of overdiagnosed PCa cases and MRI scans and biopsies, respectively, at 10-year absolute risk thresholds of 2 percent and 10 percent, whilst generating greater QALYs at all risk thresholds <5 percent,” They noted.

MRI-first risk-tailored screening vs biopsy-first age-based screening prevented a greater number of PCa deaths at a risk threshold of 2 percent, but the PCa deaths prevented were 1.7–15.3 percent less compared with MRI-first age-based screening at risk thresholds of 2 percent and 10 percent, respectively.

All MRI-first risk-tailored screening strategies had a higher net monetary benefit (NMB) than MRI-first age-based screening, as well as incremental cost-effectiveness ratios (ICERs) of <GBP 20,000 (ie, USD 26,000) per QALY gained using a risk threshold of ≥2.5 percent compared with no screening.