A pilot study of an organised population-based testing programme for prostate cancer

Abstract

Objective: To determine the feasibility of a digitally automated population-based programme for organised prostate cancer testing (OPT) in Southern Sweden.

Patients and methods: A pilot project for a regional OPT was conducted between September 2020 and February 2021, inviting 999 randomly selected men aged 50, 56, or 62 years. Risk stratification was based on prostate-specific antigen (PSA) level, PSA density (PSAD), and bi-parametric prostate magnetic resonance imaging (MRI). Men with a PSA level of 3-99 ng/mL had an MRI, and men with elevated PSA level (≥3 ng/mL) had a urological check-up, including a digital rectal examination and transrectal ultrasonography (TRUS). Indications for targeted and/or systematic transrectal prostate biopsies were suspicious lesions on MRI (Prostate Imaging-Reporting and Data System [PI-RADS] 4-5) and/or PSAD > 0.15 ng/mL/mL. Additional indications for prostate biopsies were palpable tumours, PSA ratio < 0.1, or cancer suspicion on TRUS. Patient selection, mail correspondence, data collection, and algorithm processing were performed by an automated digital management system. Feasibility is reported descriptively.

Results: A total of 418 men had a PSA test (42%), with increasing participation rates by age (50 years, 38%; 56 years, 44%; and 62 years, 45%). Among these, 35 men (8%) had elevated PSA levels (≥3 ng/mL: one of 139, aged 50 years; 10/143, aged 56 years; and 24/146, aged 62 years). On MRI, 16 men (48%) had a negative scan (PI-RADS < 3), seven men (21%) had PI-RADS 3, nine men (27%) had PI-RADS 4, and one man (3%) had PI-RADS 5. All men with PI-RADS 4 or 5 underwent prostate biopsies, as well as two men with PI-RADS 3 due to PSAD > 0.15 ng/mL/mL or a suspicious finding on TRUS. Prostate cancer was diagnosed in 10 men. Six men underwent active treatment, whereas four men were assigned to active surveillance.

Conclusion: Our OPT model is feasible from an operational point of view, but due to the limited scale of this study no conclusions can be made regarding the efficacy of the diagnostic model or outcome.

Keywords: algorithm; magnetic resonance imaging; prostate cancer; prostate-specific antigen; screening.

Figure 1

Invitations, participation, and outcomes for the OPT pilot project. Men aged 50, 56, and 62 years were randomly invited to participate in OPT with an initial PSA test. Men with PSA levels of 3–99 ng/mL were automatically referred for biparametric MRI and subsequently for urological assessment with DRE and TRUS. Targeted and/or systematic TRUS-guided biopsies were performed if indicated by the OPT-pilot algorithm (Fig. 2). Men with PSA levels below 3 ng/mL were scheduled for another invitation after 2 years (PSA = 1–2.9 ng/mL) or 6 years (PSA < 1 ng/mL). OPT: organised prostate cancer testing

Figure 2

The OPT pilot algorithm for men with elevated PSA levels. Men with elevated PSA levels (≥ 3 ng/mL, but less than 100 ng/mL) underwent biparametric prostate MRI scans, which were assessed using PI-RADS. MRI was followed by urological assessments using DREs and TRUS. Targeted (3–4 per lesion) and/or systematic (–12) transrectal biopsies were performed when indicated by the PIRADS assessments, PSAD (ng/mL/cm³), or suspicious findings on TRUS or DREs. Men with PSA levels of 100 ng/mL or greater were immediately referred for urological assessments and prostate biopsies without prior MRI. OPT: organised prostate cancer testing; PI-RADS: prostate imaging reporting and data system; PSAD: PSA density; PSA ratio: Free PSA/total PSA.

Figure 3

56-year-old man, PSA = 3.1 ng/mL, PSAD = 0.10 ng/mL/cm³. The MRI shows a PI-RADS 4 lesion in the dorsal portion of the mid-gland PZ. Targeted biopsies (n = 4) with cancer in 4/4 biopsies, Gleason 3+4=7. RARP with the index tumour corresponding to a PI-RADS 4 lesion. a. MRI DWI b1500, white arrow indicates the lesion, grey arrow indicates artifact from rectal gas. b. MRI ADC, arrow indicates the lesion. c. MRI T2-weighted, arrow indicates the lesion. d. Swedish nationwide web-based register platform for cancer patient data (INCA) database information from radiologist (lesion location is shown in yellow) and urologist (number and locations of targeted biopsies). e. Digitalised pathology image of targeted biopsy shows 7-mm tumour, Gleason 3+4. f. Digitalised image of a prostatectomy specimen. Green demarcation shows the index lesion (22 × 6 mm), dorsal portion of the mid-gland PZ. The second tumour, Gleason 3+3 (6 × 3 mm) anterior right side of the TZ, was not detected by MRI. PSAD: PSA density, PIRADS: prostate imaging reporting and data system. PZ: peripheral zone. TZ: transition zone. RARP: robot-assisted radical prostatectomy. DWI: diffusion-weighted imaging, ADC: apparent diffusion coefficient.