Population-Based Prostate Cancer Screening With Magnetic Resonance Imaging or Ultrasonography

Importance: Screening for prostate cancer using PSA-testing can lead to problems of under- and over-diagnosis. A short, non-contrast MRI or transrectal ultrasound might overcome these limitations. Objective: To compare the performance of PSA, MRI and ultrasound as screening tests for prostate cancer. Design, Setting and Participants: This prospective, population-based, blinded cohort study was conducted at seven primary care practices and two imaging centres in the UK. 2034 community based men aged 50-69 years invited for prostate cancer screening and 408 were consented. Interventions: All participants underwent screening with a PSA test, MRI (T2-weighted and diffusion) and ultrasound (b-mode and shearwave elastography).-The tests were independently interpreted without knowledge of other results. Both imaging tests were reported on a validated 5-point scale of suspicion. If any test was screen-positive, a systematic 12-core biopsy was performed. Additional image-fusion targeted biopsies were taken if the MRI or ultrasound was positive. Main Outcomes and Measures: The proportion of men with screen-positive MRI or ultrasound (defined as either score 3-5 or 4-5) or screen-positive PSA (defined as PSA≥3g/L). Key secondary outcomes were the number of clinically-significant and clinically-insignificant cancers detected if each test was used exclusively. Clinically-significant cancer was defined as any Gleason score≥3+4. Results: The proportion with a screen-positive MRI (score 3-5) was higher than the proportion with a screen-positive PSA (72/406, 17.7%[95%CI 14.3-21.8] vs. 40/406,9.9%[95%CI 7.3-13.2]; p