Prostate Cancer Screening With PSA, Kallikrein Panel, and MRI: The ProScreen Randomized Trial.

Prostate-specific antigen (PSA) screening has potential to reduce prostate cancer mortality but frequently detects prostate cancer that is not clinically important.

To describe rates of low-grade (grade group 1) and high-grade (grade groups 2-5) prostate cancer identified among men invited to participate in a prostate cancer screening protocol consisting of a PSA test, a 4-kallikrein panel, and a magnetic resonance imaging (MRI) scan.

The ProScreen trial is a clinical trial conducted in Helsinki and Tampere, Finland, that randomized 61 193 men aged 50 through 63 years who were free of prostate cancer in a 1:3 ratio to either be invited or not be invited to undergo screening for prostate cancer between February 2018 and July 2020.

Participating men randomized to the intervention underwent PSA testing. Those with a PSA level of 3.0 ng/mL or higher underwent additional testing for high-grade prostate cancer with a 4-kallikrein panel risk score. Those with a kallikrein panel score of 7.5% or higher underwent an MRI of the prostate gland, followed by targeted biopsies for those with abnormal prostate gland MRI findings. Final data collection occurred through June 31, 2023.

In descriptive exploratory analyses, the cumulative incidence of low-grade and high-grade prostate cancer after the first screening round were compared between the group invited to undergo prostate cancer screening and the control group.

Of 60 745 eligible men (mean [SD] age, 57.2 [4.0] years), 15 201 were randomized to be invited and 45 544 were randomized not to be invited to undergo prostate cancer screening. Of 15 201 eligible males invited to undergo screening, 7744 (51%) participated. Among them, 32 low-grade prostate cancers (cumulative incidence, 0.41%) and 128 high-grade prostate cancers (cumulative incidence, 1.65%) were detected, with 1 cancer grade group result missing. Among the 7457 invited men (49%) who refused participation, 7 low-grade prostate cancers (cumulative incidence, 0.1%) and 44 high-grade prostate cancers (cumulative incidence, 0.6%) were detected, with 7 cancer grade groups missing. For the entire invited screening group, 39 low-grade prostate cancers (cumulative incidence, 0.26%) and 172 high-grade prostate cancers (cumulative incidence, 1.13%) were detected. During a median follow-up of 3.2 years, in the group not invited to undergo screening, 65 low-grade prostate cancers (cumulative incidence, 0.14%) and 282 high-grade prostate cancers (cumulative incidence, 0.62%) were detected. The risk difference for the entire group randomized to the screening invitation vs the control group was 0.11% (95% CI, 0.03%-0.20%) for low-grade and 0.51% (95% CI, 0.33%-0.70%) for high-grade cancer.

In this preliminary descriptive report from an ongoing randomized clinical trial, 1 additional high-grade cancer per 196 men and 1 low-grade cancer per 909 men were detected among those randomized to be invited to undergo a single prostate cancer screening intervention compared with those not invited to undergo screening. These preliminary findings from a single round of screening should be interpreted cautiously, pending results of the study's primary mortality outcome.

ClinicalTrials.gov Identifier: NCT03423303.

JAMA. 2024 Apr 06 [Epub ahead of print]

Anssi Auvinen, Teuvo L J Tammela, Tuomas Mirtti, Hans Lilja, Teemu Tolonen, Anu Kenttämies, Irina Rinta-Kiikka, Terho Lehtimäki, Kari Natunen, Jaakko Nevalainen, Jani Raitanen, Johanna Ronkainen, Theodorus van der Kwast, Jarno Riikonen, Anssi Pétas, Mika Matikainen, Kimmo Taari, Tuomas Kilpeläinen, Antti S Rannikko, ProScreen Trial Investigators

Tampere University, Unit of Health Sciences, Faculty of Social Sciences, Tampere, Finland., Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland., Helsinki University Hospital, Department of Pathology, Helsinki, Finland., Department of Translational Medicine, Lund University, Malmö, Sweden., Department of Radiology, Helsinki University Hospital, Helsinki, Finland., Department of Radiology, Tampere University Hospital, Tampere, Finland., Laboratory Medicine Program, University Health Network, Toronto, Canada., Department of Urology, Tays Cancer Centre, Tampere University Hospital, Tampere, Finland., Department of Urology, Helsinki University Hospital, Helsinki, Finland., University of Helsinki, Faculty of Medicine, Helsinki, Finland., Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.